CLF Cleveland-Cliffs Inc. - 10-K

ITEM 1A. RISK FACTORS

An investment in our common shares or other securities is subject to risks inherent in our businesses and the industries in which we operate. We describe below certain risks and uncertainties, the occurrences of which could have a material adverse effect on us. The risks and uncertainties described below include known material risks that we face currently, but our material risks are continually evolving, and the below descriptions may not include future risks that are not presently known, risks that are not currently believed to be material or risks that generally apply to most businesses. Although we have extensive risk management policies, practices and procedures in place that are aimed at mitigating these risks, the occurrence of these uncertainties may nevertheless impair our business operations and adversely affect the actual outcome of matters as to which forward-looking statements are made. This report is qualified in its entirety by these risk factors. Before making an investment decision, investors should carefully consider all the risks described below together with the other information included in this report and the other reports we file with the SEC.

Management has identified several categories of material risks that we are subject to, including: (I) economic and market; (II) regulatory; (III) financial; (IV) operational; (V) sustainability and development; and (VI) human capital. Although we have organized the risks by these headings and we have discussed each risk separately, many of the risks are interrelated.

I. ECONOMIC AND MARKET RISKS

The volatility of commodity prices, including steel, scrap metal and iron ore, directly and indirectly affects our ability to generate revenue, maintain stable cash flows and fund our operations.

Our profitability is dependent upon the historically volatile market prices of steel, scrap metal and iron ore. We experience direct impacts of steel price fluctuations through customer sales, direct impacts of scrap metal price fluctuations through customer sales and supplier purchases, and indirect impacts from movements in scrap metal and iron ore prices that influence steel prices. As described elsewhere in this report, the prices of steel, scrap metal and iron ore have fluctuated significantly in the recent past, and these pricing shifts are unpredictable and affected by factors beyond our control, including:

• changes in the production capacity, production rate and inventory levels of other steel producers, distributors, iron ore suppliers and scrap metal processors and traders;

• changes in trade laws and volumes of unfairly traded imports;

• imposition or termination of duties or tariffs, including tariffs and retaliatory tariffs that have recently been and may in the future be instituted in response to geopolitical developments or otherwise, which, among other things, may affect our cross-border shipments, import and export controls, and other trade barriers impacting the steel, scrap metal and iron ore markets;

• international demand for, and the impact of higher rates of inflation on, raw materials used in steel production;

• availability of scrap metal substitutes such as pig iron;

• commodity price speculation; rates of global economic growth, especially light vehicle production and construction and infrastructure activity that requires significant amounts of steel;

• changes in the levels of economic activity in the U.S., Canada, China, India, Europe and other industrialized or developing economies, including as a result of geopolitical conflicts or otherwise;

• changes in China’s emissions policies and environmental compliance enforcement practices;

• climate change and other weather-related disruptions, infectious disease outbreaks or natural disasters that may impact the global supply of steel, scrap metal or iron ore; and

• the proximity, capacity and cost of infrastructure and transportation.

Our revenues, therefore, vary in accordance with the prices of the products we sell. To the extent that commodity prices, including the HRC price, coated and other specialty steel prices, international steel prices and scrap metal prices, significantly decline for an extended period, we may have to further revise our operating plans, including curtailing production, reducing operating costs and deferring capital expenditures. As a result, we also may have to record impairments on our goodwill, intangible assets, long-lived assets and/or inventory. Sustained lower prices also could cause us to further reduce existing mineral reserves if certain reserves can no longer be economically mined or processed at prevailing prices. Particularly during periods of increased inflation resulting in higher input costs, we may be unable to decrease our costs in an amount sufficient to offset reductions in revenues and may incur losses. These events could have a material adverse effect on us.

We sell a significant portion of our steel products to the automotive market, and fluctuations or changes in the automotive market could adversely affect our business operations and financial performance.

The largest end user for our steel products is the automotive industry in North America. Beyond these direct sales to the automotive industry, we make additional sales to distributors and converters, which may ultimately resell some of that volume to the automotive market. In addition to the magnitude of our exposure to the automotive industry, we face risks arising from our relative concentration of sales to certain specific automotive manufacturers, and our sales volumes and revenues may be adversely

17 | CLF 2025 FORM 10-K

Table of Contents

affected if we are unable to renew and/or renegotiate our fixed price contracts with one or more significant automotive customers or if those customers choose to move certain portions of their parts business to alternate suppliers. Automotive production and sales are cyclical and sensitive to general economic conditions and other factors, including interest rates, consumer credit, spending and preferences, and supply chain disruptions. If automotive production and sales decline, whether due to consumers facing reduced purchasing power caused by inflation, higher interest rates or otherwise, our sales and shipments to the automotive market are likely to decline in a corresponding manner. Adverse impacts that we may sustain as a result include, without limitation, lower margins because of the need to sell our steel to less profitable customers and markets, higher fixed costs from lower steel production if we are unable to sell the same amount of steel to other customers and markets, and lower sales, shipments, pricing and margins generally as our competitors face similar challenges and compete vigorously in other markets we serve. These adverse impacts could negatively affect our revenues, financial results and cash flows.

Moreover, despite our position as a leading North America-based flat-rolled steel producer, competition for automotive business has intensified in recent years, as steel producers and companies producing alternative materials have focused their efforts on capturing and/or expanding their volume share of automotive business because of less favorable conditions in other markets for steel and other metals, including commodity products. As a result, the potential exists that we may lose sales to existing or new entrants or that automotive manufacturers will take advantage of the intense competition among potential suppliers during periodic contract renewal negotiations to pressure our pricing and margins in order for us to maintain or expand our sales volumes with them, which could negatively affect our shipments, revenues, cost structure, financial results and cash flows.

Global steelmaking overcapacity and overproduction, as well as steel imports, could lead to lower or more volatile global steel prices, directly or indirectly impacting our profitability.

Significant existing global steel capacity and new or expanded production capacity in recent years could potentially cause capacity to exceed demand globally. Although certain North American steel producers have shut down production capacity, certain of our competitors have announced and are moving ahead with plans to develop new steelmaking capacity in the near term. In addition, certain foreign competitors, which may have cost advantages due to being owned, controlled or subsidized by foreign governments, have substantially increased their steelmaking capacity and/or production in the last few years and may target the U.S. and Canadian markets for imports. The risk of greater levels of imports could materialize, depending upon changes in duties or tariffs, foreign market and economic conditions, changes in trade agreements and treaties, laws, regulations or government policies affecting trade, the ability of foreign producers to circumvent North American trade sanctions and policy, the value of the U.S. dollar relative to other currencies and other variables beyond our control. In addition, higher sustained market prices of steel could cause new producers to enter the market or existing producers to further expand productive capacity, which could in turn lead to lower steel prices and increasing prices of steelmaking inputs, such as scrap metal. Excess global steel combined with reduced global steel demand and increased imports could also lead to lower steel prices. Downward pressure on steel prices could have an adverse effect on our results of operations, financial condition and profitability.

Severe financial hardship or bankruptcy of one or more of our major customers or key vendors could adversely affect our business operations and financial performance.

Sales and operations for a majority of our customers are sensitive to general economic conditions in the North American automotive, housing, construction, appliance, energy, defense and other industries. Some of our customers are highly leveraged. If there is a sustained weakening of current economic conditions, whether because of operational, cyclical, supply chain or other issues, including trade policies, inflationary pressures, higher interest rates or an infectious disease outbreak, it could cause customers to reduce, delay or cancel their orders with us, impact significantly the creditworthiness of our customers, and lead to other financial difficulties or even bankruptcy filings by our customers. Failure to receive payment from our customers for products that we have delivered could adversely affect our results of operations, financial condition and liquidity. The concentration of customers in a specific industry, such as the automotive industry, may increase our risk because of the likelihood that circumstances may affect multiple customers at the same time. Such events could cause us to experience lost sales or losses associated with the potential inability to collect all outstanding accounts receivable as well as reduced liquidity. Similarly, certain of our key vendors have previously suffered, and from time to time may in the future suffer, financial hardship, including bankruptcy. Such vendors could face operational disruption or even be forced to liquidate, which could result in such vendors defaulting on their obligations to us or in our inability to secure replacement materials or services on a timely basis, or at all, or cause us to incur increased costs to do so. Such events could adversely impact our continuity of operations, financial results and cash flows.

II. REGULATORY RISKS

U.S. government actions and other countries’ reactions in respect of trade agreements and treaties, laws, regulations, or policies affecting trade could lead to lower or more volatile global steel prices, impacting our profitability.

In recent years, the U.S. government has altered its approach to international trade policy, both generally and with respect to matters directly and indirectly affecting the steel industry, including by undertaking certain unilateral actions affecting trade, renegotiating existing bilateral or multilateral trade agreements, and entering into new agreements or treaties with foreign countries. For example, in early 2025, the U.S. government announced that the 25% Section 232 tariffs on steel imports originally imposed in 2018 on national security grounds would be re-imposed without exemptions or exclusions, beginning in March 2025. Subsequently, in June 2025, the Section 232 steel tariffs were generally increased to 50%. During 2025, Section 232 tariffs were also applied to certain products derived from steel as part of the U.S. Department of Commerce Section 232 steel inclusions process. Furthermore, in 2025, the Canadian government imposed a 25% tariff on imported steel regardless of country of origin

18 | CLF 2025 FORM 10-K

Table of Contents

and imposed tariff rate quotas for steel imports varying by country of origin. Even so, as has occurred in the past, the U.S. and/or Canadian governments may subsequently determine to negotiate exemptions and/or exclusions from such tariffs and other protective measures with certain trading partners. And if either the Section 232 tariffs, with respect to our U.S. operations, or Canadian measures, with respect to our Canadian operations, are removed, modified or substantially weakened, imports of foreign steel would likely increase and steel prices in the U.S. and Canada would likely fall, which could materially adversely affect our consolidated revenues, financial results and cash flows.

In addition, during 2020, the USMCA was implemented among the U.S., Mexico and Canada in place of the North American Free Trade Agreement. Because all our steel manufacturing facilities are located in North America and one of our principal markets is automotive manufacturing in North America, the USMCA has the potential to significantly impact our business results. However, it is difficult to predict the implications of changes in trade policy and, therefore, whether the USMCA (including any revisions or extensions of the USMCA that may be implemented in connection with the mandatory joint review process beginning in 2026), or any termination of the USMCA, or other new or renegotiated trade agreements, treaties, laws, regulations or policies that may be implemented by the U.S. government, or otherwise, will have a beneficial or detrimental impact on our business and our customers’ and suppliers’ businesses. Adverse effects could occur directly from a disruption to trade and commercial transactions and/or indirectly by adversely affecting the U.S. economy or certain sectors of the economy, impacting demand for our customers’ products and, in turn, negatively affecting demand for our products. Important links of the supply chain for some of our key customers, including automotive manufacturers, could be negatively impacted by the USMCA or other new or renegotiated trade agreements, treaties, laws, regulations or policies.

While we may currently benefit from certain antidumping and countervailing duty orders, any such relief is subject to periodic reviews and challenges, which can result in revocation or modification of the orders or reduction of the duties. The U.S. government has imposed and may in the future impose new or additional tariffs on goods imported into the U.S. (including steel or critical production inputs), which has led to and could in the future lead to other countries imposing or threatening to impose retaliatory tariffs on exports of American-made products (including steel) to those countries or other retaliatory efforts, such as restricting exports of critical production inputs to the U.S. In addition, previously granted petitions for trade relief may not be successful or fully effective at preventing harm from subsidized and dumped imports into the U.S. Any of these actions and their direct and indirect impacts could materially adversely affect our revenues, financial results and cash flows.

We are subject to extensive governmental regulation, which imposes potentially significant costs and liabilities on us. Future laws and regulations or the way they are interpreted and enforced could increase these costs and liabilities or limit our ability to produce our raw materials and products.

New laws or regulations, or changes in existing laws or regulations, or the manner of their interpretation or enforcement, could increase our cost of doing business and restrict our ability to operate our businesses or execute our strategies. This includes, among other things:

• changes in, and enforcement of, MSHA regulations, such as respirable silica standards;

• evaluation of the National Ambient Air Quality Standards, such as revised nitrogen dioxide, sulfur dioxide, lead, ozone and particulate matter criteria;

• changes in the interpretation of OSHA regulations, such as those covering respiratory protection, heat stress and potentially hazardous machinery, as well as continued enforcement of various OSHA National Emphasis Programs focused on particular hazards, including those for indoor and outdoor heat stress; and

• changes in tax laws and regulations, including the possible taxation under U.S. or foreign country laws of certain income from worldwide operations.

Our operations are subject to various laws and regulations relating to protection of the environment and human health and safety, including those relating to:

• air quality, water quality and conservation;

• plant, wetlands, natural resources and wildlife protection (including endangered or threatened species);

• reclamation, remediation and restoration of properties and related surety bonds or other financial assurances;

• land use;

• the discharge of materials into the environment; and

• the effects that industrial operations and mining have on groundwater quality and availability, such as the potential effects of laws or regulations related to per-and polyfluoroalkyl substances (“PFAS”).

Despite implementation of rigorous environmental protocols and management systems, we cannot be certain that we have been or will be at all times in complete compliance with all such laws and regulations. If we violate or fail to comply with these laws or regulations, we could be fined, required to retrofit or cease operations, subject to criminal or civil liability, or otherwise sanctioned by regulators or barred from participating in government contracts. In addition, regulatory agencies have the authority to order a mine or production facility to be temporarily or permanently closed where imminent danger that could cause death or serious physical harm is perceived. Compliance with the complex and extensive laws and regulations to which we are subject imposes substantial costs on us, which could increase over time because of heightened regulatory oversight, adoption of more stringent environmental,

19 | CLF 2025 FORM 10-K

Table of Contents

health and safety standards and greater demand for remediation services leading to shortages of equipment, supplies and labor, as well as other factors.

Specifically, there are several notable proposed or recently enacted rulemakings or activities to which we would be subject or that would further regulate and/or tax us and our customers, which may also require us or our customers to reduce or otherwise change operations significantly or incur significant additional costs, potentially limiting our ability to produce our raw materials and products, depending on their ultimate outcome. These emerging or recently enacted rules, regulations and policy guidance include, but are not limited to:

• trade regulations, trade agreements, treaties or related policies;

• changes in tariff policy, including with respect to the 50% tariff on certain imported steel imposed under Section 232, and the retaliatory tariffs that have already been, or may in the future be, imposed in response to such tariffs;

• revised National Emission Standards for Hazardous Air Pollutants in the taconite, integrated iron and steel, lime and coke sectors;

• climate change mitigation strategies, carbon taxes and GHG regulation;

• selenium discharge regulation;

• revisions to the sulfate wild rice water quality standard and its implementation;

• Minnesota’s Mercury TMDL;

• ozone transport regulations;

• state agency decisions related to environmental justice initiatives;

• reduction of SO 2 levels at steel plants in Canada;

• revised National Ambient Air Quality Standards, particularly for particulate matter, sulfur dioxide and ozone; and

• additional regulations regarding PFAS.

We similarly expect some state governments to continue to propose more stringent environmental regulation, in particular related to climate change. Any new or more stringent legislation, regulations, rules, interpretations or orders, when enacted and enforced, including any related to required monitoring and reporting or reductions in, or taxes on, levels of carbon emissions, could have a material adverse effect on our business, results of operations, financial condition or profitability. In addition, judicial decisions or executive actions limiting the authority of regulatory agencies or impacting current regulations and policies implemented by such agencies could create uncertainty regarding the regulatory landscape and impact our ability to operate our existing business and plan for future investments.

Our operations may be impacted by the recent proposal and ongoing consideration of significant federal and state laws and regulations relating to certain mine-related issues, including potential changes to the approval process for roof control and ventilation plans in underground coal mines and training plans for all mines. Additionally, there are requirements for the prompt reporting of accidents and increased fines and penalties for violations of these laws and regulations. Enforcement of existing mine-related laws and regulations, as well as enactment of any new such laws or regulations, may cause us to incur substantial additional compliance costs and fines and penalties for any violations.

In addition, certain of our operations are subject to the risks of doing business abroad and we must comply with complex foreign and U.S. laws and regulations, which may include, but are not limited to, the Foreign Corrupt Practices Act and other anti-bribery laws, regulations related to import/export and trade controls, the European Union’s General Data Protection Regulation and other U.S. and foreign privacy regulations, and transportation and logistics regulations. These laws and regulations may increase our costs of doing business in international jurisdictions and expose our operations and employees to elevated risk. We require our employees, contractors and agents to comply with these and all other applicable laws and regulations, but failure to do so could result in possible administrative, civil or criminal liability and reputational harm to us and our employees.

As a supplier on public procurement projects, we may be subject to certain stringent regulations that may present compliance challenges or may increase the costs of securing certain business. These public procurement projects include projects that may arise out of proposed or recently enacted governmental legislation regarding infrastructure investments, which may require unique compliance obligations when compared with private sector projects. For example, in order to remain eligible for DOE funding, our major Butler and Middletown capital projects are subject to extensive U.S. government and DOE-specific regulations with which we must comply, including with respect to restrictions related to the use of foreign contractors and workers. Also, the U.S. government has rights to, and imposes ownership and use restrictions on, intellectual property that may be developed in connection with these projects. Further, our business is subject to risks associated with changes in laws, regulations and government policies, including executive orders. For example, executive orders may impose new compliance obligations, restrict our ability to perform under existing government contracts, impact our eligibility for future government awards, or require changes to our business practices. The additional burdens and restrictions imposed by these types of regulations and executive orders could increase our costs, delay our projects, limit our operational and contracting flexibility, and disincentivize certain technology providers or other vendors from working with us. We may also be indirectly affected through regulatory changes that impact our customers, which in turn could reduce the quantity of our products they demand, adversely impact the terms upon which they purchase or the prices for our products they are willing to pay. Regulatory changes that impact our suppliers, such as any changes in labor or environmental

20 | CLF 2025 FORM 10-K

Table of Contents

standards in China, could decrease the availability of products or services they sell to us or could increase the price they demand for products or services they sell to us.

Our operations use hazardous materials and inadvertently may impact the environment, which could result in material liabilities to us.

Our operations currently use, and have in the past used, hazardous materials and substances, and we have generated, and expect to continue to generate, solid and hazardous waste. We have been, and may in the future be, subject to claims under laws and regulations for toxic torts, natural resource damages and other damages as well as for the investigation and clean-up of soil, surface water, sediments, groundwater and other natural resources and reclamation of properties. Such claims for damages, as well as investigation, remediation and reclamation requirements, have arisen and may arise in the future out of current, future or former conditions at sites that we or our acquired companies own, lease or operate, as well as sites that we or our acquired companies formerly owned, leased or operated, and at contaminated sites that are or have been owned, leased or operated by our joint venture partners. We may also have liability for contamination at third-party sites where we have sent hazardous wastes. Our liability for these claims may be strict and/or joint and several, such that we may be held responsible for more than our share of the contamination or other damages, or even for entire claims regardless of fault. We may be named as a potentially responsible party at other third-party sites in the future, and we cannot be certain that the costs associated with these additional sites will not exceed any reserves we have established or otherwise be material.

We may be unable to obtain, maintain, renew or comply with permits and licenses necessary for our operations or be required to provide additional financial assurances, which could reduce our production, cash flows, profitability and available liquidity.

We must obtain, maintain and comply with numerous permits and licenses that require approval of operational plans and impose strict conditions on various environmental, health and safety matters in connection with our steel production and processing and mining and other operations. These include permits and approvals issued by various agencies and regulatory bodies, with which we may not always be able to comply. The permitting rules are complex and may change over time, making our ability to comply with the applicable requirements more difficult or potentially impractical and costly, possibly precluding the continuance of ongoing operations or the development of future operations. Interpretations of rules may also change over time and may lead to requirements, such as additional financial assurances, making it costlier to comply. Moreover, despite our ongoing efforts to reduce our environmental footprint and improve the resiliency of our business model, heightened levels of regulatory oversight focused on addressing climate change and industrial activities that generate air emissions and/or water discharges, such as our steelmaking, cokemaking and mining operations, could impact, delay, or disrupt our ability to obtain new or renewed permits or modifications to existing permits.

In addition, the public, including special interest groups, Tribal nations and individuals, have certain rights under various laws to comment upon, submit objections to, and otherwise engage in the permitting process, including bringing citizens’ lawsuits to challenge such permits or activities. For example, we have encountered and expect to continue to encounter public objections to permit renewal applications relating to our major mining operations and steelmaking facilities. Due to these factors or for other reasons, required permits may not be issued or renewed in a timely fashion or at all, or permits issued or renewed may include conditions that we cannot meet, may require additional capital investments, or may restrict our ability to conduct our production, mining and processing activities efficiently. Such conditions could include requirements for additional financial assurances that we may not be able to provide on commercially reasonable terms or at all, which could reduce available borrowing capacity under our ABL Facility. Such conditions, restrictions or requirements could also reduce our production, cash flows or profitability.

III. FINANCIAL RISKS

Our existing and future indebtedness may limit cash flow available to invest in the ongoing needs of our businesses, which could prevent us from fulfilling our obligations under our senior notes, ABL Facility and other debt, and we may be forced to take other actions to satisfy our obligations under our debt, which may not be successful.

As of December 31, 2025, we had $6.9 billion aggregate principal amount of senior notes and $452 million aggregate borrowings under our ABL Facility outstanding (excluding $65 million of outstanding letters of credit and $402 million of finance leases) and $57 million of cash on our statement of consolidated financial position. The aggregate principal amount of revolver commitments under our ABL Facility is $4.75 billion, comprised of $4.25 billion of lending commitments available to be borrowed by us and certain of our U.S. subsidiaries, and $500 million of lending commitments available to be borrowed by certain of our Canadian subsidiaries. As of December 31, 2025, the aggregate borrowing availability under our ABL Facility was $3.2 billion based on amounts currently drawn, outstanding letters of credit obligations and our borrowing base.

A portion of our cash flow from operations is used to service debt under our senior notes and ABL Facility, reducing the availability of cash to fund capital expenditures, acquisitions or strategic development initiatives, and other general corporate purposes, or to retire debt or return capital to shareholders, including via share repurchases. While we currently expect the U.S. Federal Reserve to lower interest rates during 2026, decisions regarding the trajectory of future interest rates are uncertain, and there is risk that interest rates could be maintained or even increased. Higher-than-expected interest rates would increase the amount of cash we would need to allocate to servicing the interest expense on our debt for so long as we have an outstanding balance drawn under our ABL Facility.

21 | CLF 2025 FORM 10-K

Table of Contents

Our ability to make scheduled payments on the principal, premium, if any, and interest on our debt, or to refinance our debt obligations, depends on our ability to generate cash in the future and our financial condition and operating performance, which are subject to prevailing economic and competitive conditions and to certain financial, business and other factors beyond our control, as described elsewhere in this “Risk Factors” section. If we are unable to service our debt obligations, we could face substantial liquidity problems and we may be forced to reduce or delay investments, capital expenditures and share repurchases, or to sell assets, seek additional capital, including additional secured or unsecured notes, or restructure or refinance our debt, and we may be unable to continue as a going concern. We may be unable to consummate any proposed strategic partnership transactions or asset divestitures, and any proceeds may not be adequate to meet any debt service obligations then due. Any of these examples potentially could have a material adverse impact on our results of operations, profitability, shareholders’ equity and capital structure. In addition, a failure to comply with any applicable covenants in the instruments governing our debt could result in an event of default that, if not cured or waived, would have a material adverse effect on us.

Our level of indebtedness could have further consequences, including, but not limited to, increasing our vulnerability to adverse economic or industry conditions, placing us at a competitive disadvantage compared to other businesses in the industries in which we operate that are not as leveraged and that may be better positioned to withstand economic downturns and recessionary environments, limiting our flexibility to plan for, or react to, changes in our businesses and the industries in which we operate, and requiring us to refinance all or a portion of our existing debt. We may not be able to refinance on commercially reasonable terms or at all, and any refinancing of our debt could be at higher interest rates and may require us to comply with more onerous covenants, making it more difficult to obtain surety bonds, letters of credit or other financial assurances that may be demanded by our vendors or regulatory agencies, particularly during periods in which credit markets are weak. In addition, our cost of financing or refinancing, access to the capital markets, and the terms under which we purchase goods and services could be adversely affected when credit ratings agencies downgrade our ratings, whether due to factors specific to our business or debt profile, a prolonged cyclical downturn in the steel, scrap metal and mining industries or macroeconomic trends (such as global or regional recessions), increases in pension and OPEB obligations, adverse impacts of inflation and high interest rates, or trends in credit and capital markets more generally. A portion of our borrowing capacity and any outstanding indebtedness under our ABL Facility bears interest at a variable rate based on SOFR. To the extent these interest rates increase, our interest expense will increase. Restricted access to capital markets and/or increased borrowing costs could have an adverse effect on our results of operations, cash flows, financial condition and liquidity.

We continue to face ongoing risks arising out of the Stelco Acquisition and may be unable to realize the anticipated financial and other benefits from proposed strategic partnerships and asset divestitures.

We completed the Stelco Acquisition in the fourth quarter of 2024. We remain subject to significant risks and uncertainties arising out of the Stelco Acquisition that may adversely affect us, including in connection with the following:

• our ability to service additional debt incurred;

• our ability to manage additional known and unknown liabilities assumed;

• challenges of operating in multiple countries with potentially conflicting laws, including in respect of tariff and trade matters; and

• our ability to satisfy our operational, employment, environmental, charitable or other undertakings made to the Canadian government.

If one or more of these risks were to materialize, we could experience higher costs, lower profitability, reputational damage, and other adverse impacts to our operations and businesses, which could cause the price of our common shares to decline. We would expect that similar risks would apply to the extent that we engage in any future acquisitions activity.

We are also subject to risks and uncertainties relating to our non-binding Memorandum of Understanding with POSCO. Although we believe a successful transaction would be highly accretive to our shareholders, the strategic partnership contemplated by the Memorandum of Understanding remains subject to negotiation of definitive terms regarding such strategic partnership, together with the execution and closing of definitive agreements between the parties. As such, there can be no assurances that the parties will enter into such definitive agreements, that the strategic partnership will be implemented in accordance with the terms of the Memorandum of Understanding, or that the strategic partnership will proceed as currently expected or will ultimately be successful. While we expect to realize certain financial benefits arising out of the proposed partnership under the Memorandum of Understanding, including substantial proceeds that could be used to reduce our outstanding indebtedness, there is risk that the proposed partnership with POSCO does not come to fruition in a timely manner or at all or that any ultimate financial benefits could be less significant than we currently anticipate.

We are also subject to risks and uncertainties relating to potential divestitures of our non-core operating assets and idled, closed or otherwise inactive sites. While we anticipate using future proceeds from any such divestiture transactions to reduce our outstanding indebtedness, it is uncertain whether we will be successful in completing any such potential transactions in a timely manner or at all. Even if we are successful in completing any such divestitures, there is a risk that our actual realized cost savings and/or cash proceeds may be less than we have forecasted. Furthermore, we may incur asset impairment charges related to divestitures that reduce our profitability. We may also be unable to recover the carrying value of any divested assets, which potentially could have an adverse impact on our financial results and shareholders’ equity. In addition, our divestiture activities may present financial, managerial and operational risks, including diversion of management attention from our core businesses, difficulties separating personnel and financial, IT and other systems, adverse effects on existing business relationships with

22 | CLF 2025 FORM 10-K

Table of Contents

suppliers and customers, trailing indemnity obligations and potential disputes with transaction counterparties. Any of these factors could adversely affect our financial condition, business productivity and results of operations.

Our actual operating results may differ significantly from our guidance.

From time to time, we release guidance, including that set forth under “Management’s Discussion and Analysis of Financial Condition and Results of Operations–Outlook” in our Annual Reports on Form 10-K and our Quarterly Reports on Form 10-Q, regarding our future performance. This guidance, which consists of forward-looking statements, is prepared by our management and is qualified by, and subject to, the assumptions and the other information included in our Annual Reports on Form 10-K and our Quarterly Reports on Form 10-Q. Our guidance is not prepared with a view toward compliance with published guidelines of the American Institute of Certified Public Accountants, and neither our independent registered public accounting firm nor any other independent or outside party compiles or examines the guidance and, accordingly, no such person expresses any opinion or any other form of assurance with respect thereto.

Guidance is based upon assumptions and estimates that, while presented with numerical specificity, are inherently subject to business, economic, regulatory and competitive uncertainties and contingencies, many of which are beyond our control and are based upon specific assumptions with respect to future business decisions, some of which will change. The principal reason that we release such data is to provide a basis for our management to discuss our business outlook with analysts and investors. We do not accept any responsibility for any projections or reports published by any such third parties.

Guidance is necessarily speculative in nature, and it can be expected that some or all the assumptions of the guidance furnished by us will not materialize or will vary significantly from actual results. Accordingly, our guidance is only an estimate of what management believes is realizable as of the date of release. Actual results will vary from the guidance. Investors should also recognize that the reliability of any forecasted financial data diminishes the further in the future that the data are forecast. Considering the foregoing, investors are urged to put the guidance in context and not to place undue reliance on it. Any failure to successfully implement our operating strategy or the occurrence of any of the risks described in our Annual Reports on Form 10-K or our Quarterly Reports on Form 10-Q could cause actual operating results to differ from the guidance, and such differences may be adverse and material.

We may be subject to various lawsuits, claims, arbitrations or governmental proceedings that could result in significant expenditures.

We are from time to time subject to various lawsuits, claims, arbitrations or governmental proceedings relating to commercial and business disputes, antitrust claims, environmental matters, government investigations, occupational or personal injury claims, property damage, labor, employment and pension matters, mineral royalty disputes, or suits involving legacy operations and other matters. For example, certain of our subsidiaries have been named in lawsuits claiming exposure to asbestos, many of which have been dismissed and/or settled for non-material amounts. Nevertheless, it is likely that similar types of claims will continue to be filed in the future, and we could experience material adverse judgments or incur significant costs to defend such claims or any other existing and future lawsuits, claims, arbitrations or governmental proceedings, including those discussed in Part I - Item 3. Legal Proceedings , which could adversely affect our results of operations, cash flows, financial condition and liquidity. The insurance we maintain may not cover certain claims and, even when coverage applies, it may not be adequate to protect us in the event of significant claims.

IV. OPERATIONAL RISKS

Our operating expenses could increase significantly if the prices of raw materials, electrical power, fuel or other energy sources rise.

Our operations require significant use of energy, water and raw materials. Although we are largely self-sufficient in iron ore and partially self-sufficient in coke, metallurgical coal and scrap metal, we are wholly or partially dependent on third-party suppliers for certain critical raw materials and production inputs, including industrial gases, graphite electrodes, chrome, zinc, coke, metallurgical coal, scrap metal, fluxing compounds and other alloys. Prices for electricity, natural gas, diesel fuel, oils and raw materials can fluctuate widely with availability and demand levels from other users, including fluctuations caused by the impact of inflationary pressures, supply chain constraints, infectious disease outbreaks and geopolitical conflicts. For example, increased electricity demand to the grid in response to physical climate-related risks, adverse or extreme weather events, and electrification of the economy (such as unprecedented power and water demands for data centers) could adversely impact energy prices. During periods of peak usage, although some operations have contractual arrangements in place whereby they receive certain offsetting payments in exchange for electricity load reduction, supplies of energy and raw materials in general may be curtailed and we may not be able to purchase them at historical rates. A disruption in the transmission of energy, inadequate energy transmission infrastructure, or the termination of any of our energy supply contracts could interrupt our energy supply and adversely affect our operations. While we have some long-term contracts with electrical, natural gas and raw material suppliers, we are exposed to fluctuations in energy, natural gas and raw material costs that can affect our production costs. We regularly enter into market-based pricing supply contracts for electricity, natural gas and diesel fuel for use in our operations. Those contracts expose us to price increases in energy costs, which could adversely impact our profitability. In addition, public utilities may impose rate increases and/or pass through additional capital and operating cost increases to their customers related to new capacity build-outs for data centers, environmental regulations or other charges that may require significant capital investment and/or use of cleaner fuels in the future. New or revised regulations or other government actions related to air emission standards could result in rate and/or cost increases from public utilities, which could significantly increase the costs of operating our manufacturing and mining facilities. Although we regularly monitor and from time to time challenge rate cases initiated by these utilities or other sources

23 | CLF 2025 FORM 10-K

Table of Contents

seeking to increase the amounts that our facilities must pay for electricity, natural gas or water, there is no assurance that our challenges will be successful in reducing or eliminating proposed rate and/or cost increases.

The majority of our steel shipments are sold under contracts that do not allow us to pass through all increases in raw materials, supplies and energy costs. Some of our customer contracts include variable-pricing or surcharge mechanisms allowing us to adjust the total sales price based on changes in specified raw materials, supplies and energy costs. Those adjustments, however, rarely reflect all our underlying raw materials, supplies and energy cost changes. The scope of the adjustment may also be limited by the terms of the negotiated language, including limitations on when and to what extent the adjustment occurs. Further, due to recent inflationary pressures, many of our vendors have been seeking substantial price increases in order to continue providing critical goods and services, and to the extent we are required to pay relatively more for our steelmaking inputs and are unable to recognize corresponding sales price increases, we would realize lower margins on sales of our products, negatively impacting our results of operations. Our need to consume existing inventories may also delay the impact of a change in prices of raw materials or supplies. Significant changes in raw material costs may also increase the potential for inventory value write-downs in the event of a reduction in selling prices and our inability to realize the cost of the inventory. As we source a portion of our critical supplies, manufacturing equipment and raw materials from China, such as refractories, electrodes, chemicals and spare parts, existing tensions or further adverse geopolitical developments between the U.S. and China triggering or exacerbating sanctions or trading restrictions could lead to us experiencing disruptions, delays or higher costs in supplying our operations and maintaining steady-state production. In addition, even though we are partially self-sufficient in scrap metal, if the market price of scrap metal were to experience a sustained price increase, our cost to produce steel would be adversely affected due to the higher prices we would need to pay to acquire third-party scrap metal for consumption in our operations, which would adversely affect the margins we would realize on our fixed price contracts.

Our sales and competitive position depend on transporting our products to customers at competitive rates and in a timely manner, and our ability to optimize our operational footprint depends on predictably and cost effectively moving products and raw materials internally among our facilities.

Disruption of the rail, trucking, lake and other waterway transportation services because of weather-related problems, including ice and winter weather conditions on the Great Lakes or St. Lawrence Seaway, climate change, strikes, lock-outs, driver shortages and other disruptions in the trucking industry, train crew shortages or other rail network constraints, infectious disease outbreaks, or other events and lack of alternative transportation options could impair our ability to move products internally among our facilities and to supply products to our customers at competitive rates or in a timely manner and, thus, could adversely affect our operations, revenues, margins and profitability. For example, if the vessel shipping season on the Great Lakes were to be interrupted or shortened as compared to historical levels, whether due to extended winter conditions, operational failure of critical shipping locks or otherwise, our ability to transport iron ore pellets to our steel mills could be adversely affected, resulting in potential operational disruptions and reduced production volumes. Further, dredging issues and environmental changes, particularly at Great Lakes ports or along navigable rivers, could adversely impact our ability to move certain of our products or result in higher freight rates. Similarly, we depend on third-party transportation services for delivery of raw materials, other production inputs and spare parts to us, and failures or delays in delivery would have an adverse effect on our ability to maintain steady-state production and processing operations to meet customer obligations.

The cost or time to implement a strategic or sustaining capital project may prove to be greater than originally anticipated.

Most of our mines and production and processing facilities have been in operation for several decades, and the equipment is aged, requiring that we continually and successfully implement extensive and costly maintenance practices, programs and upgrades, which may take longer or be more costly than expected. From time to time, we undertake capital projects to enhance, expand, maintain or upgrade our production, mining and processing capabilities. For example, we are engaged in major initiatives at each of our Butler and Middletown facilities to leverage DOE funding to complete capital projects intended to increase our competitiveness and reduce emissions relating to our steelmaking operations. Our ability to complete these and other capital projects that we may undertake on time and on budget and achieve the anticipated production volumes, revenues or otherwise realize acceptable returns is subject to a number of risks, many of which are beyond our control, including a variety of market, operational, funding, permitting and labor-related factors. Further, the cost to implement any given capital project may prove to be greater or may take more time than originally anticipated, including due to supply chain issues that may be experienced by our vendors, and the scope of a capital project may expand or otherwise be modified. Capital projects undertaken at existing active operations, such as Butler and Middletown, may also interrupt production capabilities, which could have an adverse effect on costs and profitability. Inability to achieve the expected results from the implementation of our capital projects, incurring unanticipated costs or delays, or the inability to meet contractual obligations could adversely affect our results of operations, future earnings and cash flow generation.

Natural or human-caused disasters, weather conditions, disruption of energy, unanticipated geological conditions, equipment failures, infectious disease outbreaks and other unexpected events may lead our customers, our suppliers, or our facilities to curtail production or shut down operations.

Operating levels within our industry and the industries of our customers and suppliers are subject to unexpected conditions and events that are beyond the industries’ control. Those events, including the occurrence of an infectious disease outbreak, widespread illness or public health emergency, could cause industry members or their suppliers to curtail production or shut down a portion or all of their operations, which could reduce the demand for our products and adversely affect our revenues, margins and profitability.

24 | CLF 2025 FORM 10-K

Table of Contents

Our operating levels are subject to conditions beyond our control that can delay deliveries or increase the cost of production for varying lengths of time. Factors that could cause production disruptions could include adverse weather conditions influenced by climate change or otherwise (such as severe winter weather, tornadoes, floods, temperature extremes and the lack of availability of process water due to drought) and natural and human-caused disasters, lack of adequate raw materials, energy or other supplies, and infectious disease outbreaks. Additional factors that could adversely impact production and operations at our mining facilities and expose us to third-party liability include tailings dam failures, pit wall failures or ground subsidence, unanticipated geological conditions, including variations in the amount of overburden overlying deposits of iron ore and metallurgical coal, and processing changes.

Our mining operations, processing facilities, logistics capabilities and steelmaking operations depend on critical pieces of equipment. This equipment may, on occasion, be out of service because of unanticipated failures or unplanned outages, including due to long lead times for replacement of critical spares. From time to time, we may experience lengthy shutdowns or periods of reduced production because of equipment failures or unplanned maintenance activities. Further, remediation of any interruption in production capability may require us to make large capital expenditures that could have a negative impact on our profitability and cash flows. Our business interruption insurance may not be available to cover lost revenues associated with maintenance difficulties or damage to or failures of equipment. Longer-term business disruptions could result in a loss of customers, which could adversely affect our future sales levels and revenues.

Many of our production facilities and mines are dependent on a sole source for electric power, natural gas, water, industrial gases and/or certain other raw materials or supplies. A significant interruption in service from our suppliers due to production or transportation issues, workforce difficulties, terrorism or sabotage, weather conditions that may be influenced by climate change, natural disasters, equipment damage or failure, cyberattack or any other cause could result in substantial losses that may not be fully recoverable, either from our business interruption insurance or responsible third parties.

A disruption in or failure of our IT systems, including those related to cybersecurity, could adversely affect our business operations, reputation and financial performance and could expose us to third-party liability.

We rely on the availability, confidentiality, integrity and security of our IT systems for the operation of many of our business processes and to comply with regulatory, legal and tax requirements. While we internally maintain some of our critical IT systems, we are also dependent on third parties to provide important IT services relating to, among other things, off-site content hosting, operational process technology at our facilities, human resources, electronic communications and certain finance functions. Further, we operate certain IT hardware and software systems that can be supported only by a very limited number of specialists still remaining in the market with the required skill sets, and our continued reliance on these IT systems may increase the risk of IT system disruption or failure, which could adversely affect our operations.

Despite the security measures that we have implemented, including those related to cybersecurity and data privacy, our IT systems could be breached or damaged by computer viruses, ransomware, natural or human-caused incidents or disasters, or unauthorized physical or electronic access or intrusions, any of which could result in the loss, theft or corruption of sensitive or essential business or personal information and the inability to access or control our IT systems or information. Given our status as a critical supplier of steel to U.S. business and defense interests, we may be the target of malicious cyber activities sponsored by nation-state actors, including the Russian and Chinese governments or other state actors, as described in threat advisories periodically issued from time to time by the U.S. Cybersecurity & Infrastructure Security Agency. For example, U.S. government agencies have warned that certain state-sponsored actors are pre-positioning themselves within critical infrastructure networks to enable potential disruption during a future geopolitical crisis. Cybersecurity threat actors also may attempt to exploit vulnerabilities through software, including software commonly used by companies in cloud-based services and bundled software. Though we have controls in place and regularly conduct employee training, we cannot provide assurance that a cybersecurity incident or cyberattack will not occur or cause damage or business interruption. Furthermore, despite our efforts to audit certain critical vendors’ information security controls, significant risk may remain with respect to security measures employed by third-party service providers (including risks from software supply chain compromises or vulnerabilities introduced through vendor software updates), which may ultimately prove to be ineffective at countering threats.

Failures of our IT systems, whether caused maliciously or inadvertently, may result in the disruption of our business processes, or in the unauthorized release of sensitive, confidential, personally identifiable or otherwise protected information, or result in the corruption of data, or a cybersecurity incident, each of which could adversely affect our businesses. For example, cybersecurity vulnerabilities or other cybersecurity incidents could result in an interruption of the functionality of our automated manufacturing, operating, or health, safety and environmental systems, which, if compromised, could cease, threaten, delay or slow down our ability to produce or process steel or any of our other products for the duration of such interruption or lead to unanticipated health, safety or environmental incidents. This, in turn, could result in reputational harm and lead to litigation, including individual claims or class actions, commercial litigation, administrative, civil or criminal investigations or actions, regulatory intervention and sanctions or fines, investigation and remediation costs, and may adversely affect our employees, results of operations, financial condition and cash flows. In addition, any compromise of the security of our IT systems could result in a loss of confidence in our security measures or in the unauthorized release of third-party confidential information stored in our systems, which could subject us to litigation, regulatory investigations and negative publicity that could adversely affect our reputation and expose us to third-party liability. Our customers, suppliers and vendors may also access or store certain of our sensitive information on their IT systems, which, if breached, attacked or accessed by unauthorized persons, could likewise expose our sensitive information and adversely impact our businesses.

As cybersecurity threats continue to evolve and may become more sophisticated, including in connection with the ongoing development of AI, we may be required to incur significant costs and invest additional resources to protect against and, if required,

25 | CLF 2025 FORM 10-K

Table of Contents

remediate the damage caused by such disruptions or system failures in the future. The amount of insurance coverage we maintain and require our vendors to maintain may be inadequate to cover claims or liabilities resulting from cybersecurity incidents and attacks, and there is no guarantee that such coverage will continue to be available on commercially reasonable terms or at all. Furthermore, as we evaluate AI technologies for potential use in our operations, we face new and emerging risks, including evolving regulatory requirements and the possibility that threat actors may exploit AI-enhanced cyberattack techniques. Although we believe we are taking a deliberate and measured approach to AI adoption, any failure to implement appropriate governance frameworks or security protocols could adversely affect our operations or expose us to regulatory scrutiny and third-party liability. Additionally, to the extent our competitors successfully adopt AI and experience enhanced efficiencies and/or reduced costs, we may be at a competitive disadvantage that could adversely impact our financial results.

The closure of an operating facility or mine entails substantial costs. If our assumptions underlying our accruals for closure costs prove to be inaccurate or we prematurely close one or more of our facilities or mines, our results of operations and financial condition would likely be adversely affected.

If faced with overcapacity in the market, regulatory challenges, unfairly traded imports displacing domestic customer demand or other adverse conditions, as we have done in the past, we may seek to further rationalize our manufacturing and production assets through additional sales, temporary shutdowns, idles or facility closures. If we idle or permanently close any of our facilities or mines, our production and revenues would be reduced unless we were able to increase production at our other facilities or mines in an offsetting amount, which may not be possible, and could result in customers responding negatively by taking current or future business away from us if we seek to transition production to a different facility. Alternatively, we could fail to meet customer specifications at the facilities to which products are transitioned, resulting in customer dissatisfaction or claims. To the extent an idled or closed facility formerly supplied critical inputs to our upstream production facilities, we may need to secure alternate sources for such critical inputs, the cost and availability of which may be uncertain.

The closure of a steelmaking or other operating facility or mining operation involves significant closure costs, including reclamation and other environmental costs, the costs of terminating long-term obligations, including customer, energy and transportation contracts and equipment and real property leases, costs associated with the altered tax profile of an idled or closed facility, and certain accounting charges, including asset impairment and accelerated depreciation. In addition, a permanent facility or mine closure could accelerate and significantly increase employment legacy costs, including our expense and funding costs for pension and OPEB obligations and multiemployer pension withdrawal liabilities. In these situations, employees could be eligible for immediate retirement under special eligibility rules that apply upon a steelmaking facility or mine closure. The employees eligible for immediate retirement under the pension plans at the time of the permanent closure also could be eligible for OPEB, thereby accelerating our obligation to provide these benefits. Certain closures could precipitate a pension closure liability significantly greater than an ongoing operation liability and may trigger certain severance liability obligations. For example, during 2025, we indefinitely idled and subsequently announced the permanent closure of our Conshohocken, Pennsylvania, Riverdale, Illinois and Steelton, Pennsylvania steelmaking facilities, which collectively caused us to recognize approximately $300 million in respect of employee-related costs, asset impairments and exit costs.

In addition, we are party to several joint ventures relating to iron ore mining, downstream steel processing and scrap metal recycling, and if our joint venture partners experience financial hardships or fail to perform their obligations upon closure or otherwise, we may be required to assume significant additional obligations on behalf of the joint venture, including costs of environmental remediation and pension and OPEB obligations.

Although we base our assumptions regarding the life of our mines on detailed studies we perform from time to time, which are reviewed and validated by QPs, those studies and assumptions are subject to uncertainties and estimates that may not be accurate. We recognize the costs of reclaiming open pits, stockpiles, tailings ponds, roads and other mining support areas based on the estimated mining life of our properties. If our assumptions underlying our accruals for closure costs, including reclamation and other environmental costs, prove to be inaccurate or insufficient, or our liability in any particular year is greater than currently anticipated, our results of operations and financial condition could be adversely affected. In addition, if we were to significantly reduce the estimated life of any of our mines, the mine closure costs would be applied to a shorter period of production, which would increase costs per ton produced and could adversely affect our results of operations and financial condition.

We incur certain costs when production capacity is idled, as well as increased costs to resume production at previously idled facilities.

Our decisions concerning which facilities to operate and at what production levels are made based in part upon our customers’ orders for products, as well as the quality, performance capabilities and cost of our operations. During depressed market conditions, we may concentrate production at certain facilities and not operate others in response to customer demand or other reasons, and as a result we may incur idle costs that could offset our anticipated savings from not operating the idled facility. For example, we indefinitely idled our Minorca, Minnesota iron ore mine and a portion of our Hibbing, Minnesota iron ore mine in 2025 to consume excess pellet inventory produced during 2024, and we continue to incur certain fixed costs at those facilities during their idle periods. We cannot predict whether our operations will experience additional similar or dissimilar disruptions in the future. When we restart idled facilities, we incur certain costs to replenish inventories, prepare the previously idled facilities for operation, perform the required repair and maintenance activities, and prepare employees to return to work safely and resume production responsibilities. The amount of any such costs could be significant, depending on a variety of factors, such as the period of idle time, necessary repairs and available employees, and is difficult to project.

26 | CLF 2025 FORM 10-K

Table of Contents

We may not have adequate insurance coverage for some business risks.

Our operations are generally subject to a number of hazards and risks that could result in personal injury or damage to, or destruction of, equipment, properties or facilities. Depending on the nature and extent of a loss, the insurance that we maintain to address risks that are typical in our businesses may not be adequate or available to fully protect or reimburse us, or our insurance coverage may be limited, canceled or otherwise terminated. Insurance against some risks, such as liabilities for environmental pollution, tailings basin breaches, or certain hazards or interruption of certain business activities, may not be available at an economically reasonable cost, or at all. Even if available, we may self-insure or maintain high deductibles where we determine it is most cost effective to do so. As a result, despite the insurance coverage that we carry, accidents or other negative developments involving our production, mining, processing or transportation activities causing losses in excess of policy limits, or losses arising from events not covered under insurance policies or subject to substantial deductibles, could have a material adverse effect on our financial condition and cash flows. In addition, potential changes in extreme weather events influenced by climate change or otherwise may adversely impact our access to cost effective insurance in the future. The risk of increased insurance costs may have greater impact where the adverse event results in us asserting an insurance claim, the cost of which our insurers may seek to recoup during a future insurance renewal through increased premiums or limitations on coverage.

V. SUSTAINABILITY AND DEVELOPMENT RISKS

As we and our stakeholders seek reduced carbon footprints and enhanced business sustainability, we face financial, regulatory, legal, and reputational risks and potential loss of business opportunities because our operations utilize carbon-based energy sources and produce GHG emissions.

As described in detail in Part I - Item 1. Business - Environmental Matters - Regulatory Developments - Climate Change and GHG Regulations above, because our operations use carbon-based energy and produce GHG emissions, we are subject to risks relating to decarbonization initiatives being undertaken by regulators and other stakeholders as part of global efforts to address the potential impacts of climate change. For example, as part of climate change mitigation strategies, governmental authorities may introduce mandatory carbon pricing obligations, carbon emissions limitations, carbon taxes or carbon trading mechanisms, such as the carbon taxes we are required to pay in respect of Stelco’s emissions, any of which could impose significant costs on our operations, including causing us to incur higher energy and supplier costs, invest in costly and potentially unproven emissions control or reduction technologies, and engage in more intensive environmental monitoring and reporting efforts. In addition, complying with current or future international treaties and laws or regulations concerning climate change and GHG emissions could negatively impact our ability, and that of our customers and suppliers, to compete with companies located in areas not subject to or not complying with such constraints. We may also face more limited access to, or increased costs of, capital to the extent financial institutions and investors increase expectations relating to lowering GHG emissions or reduce investments in carbon-intensive businesses or industries. Further, increased pressure from customers or other business partners seeking to reduce their indirect carbon footprints and achieve certain overall decarbonization targets, including by sourcing a larger percentage of steel products from recycled steel, could result in the potential loss of business opportunities if we are unable to meet their carbon, GHG emissions or sustainability expectations, or if we are perceived to have higher GHG intensity than our competition.

In addition, as part of our decarbonization strategy, we are investigating and from time to time may consider investments in or other relationships with various energy efficiency and clean energy initiatives. In 2024, the DOE awarded us funding to pursue two innovative projects intended to enhance business competitiveness and reduce emissions related to our Butler facility in Pennsylvania and our Middletown facility in Ohio. We also continue to engage with developers on energy projects, including potential behind-the-meter solar projects that could be located onsite at certain of our operating facilities. While we are actively pursuing these decarbonization and energy-related projects and working closely with the DOE to align these facility investments with the U.S. federal government’s goals, there are no guarantees that sufficient funding or the necessary advanced technology will be available to complete any of these projects under currently anticipated timeframes or at all. Additionally, we may not be successful in achieving our current or any future short, medium or long-term GHG emissions reduction goals, including any net-zero or near-zero goals, due to adverse changes in business conditions over time, unanticipated financial challenges or operational improvement efforts that may not be as successful as originally forecasted, or regulatory developments arising after such goals were initially announced.

To maintain consistent operational performance and foster growth in our businesses, we must maintain our social license to operate with our stakeholders.

Maintaining a strong reputation and consistent operational, environmental and safety track records is vital to continuing to foster business growth and maintaining our permission to operate. As stakeholders’ sustainability expectations increase and regulatory requirements continue to evolve, maintaining our social license to operate becomes increasingly important. Our ability to maintain our reputation and strong operating track record could be threatened, including by circumstances outside of our control, such as disasters caused or suffered by other companies in the steel and mining industries. Our social license to operate could also be adversely affected and claims have been and could continue to be made against us to the extent that environmental factors negatively impact local communities, such as air emissions, discharges to water, dust, odors, noise and other factors that are inherent in industrial activities like our steelmaking, cokemaking, scrap metal processing and mining operations, even if such activities are conducted in accordance with legal, regulatory and permit requirements. If we are not able to respond effectively to these and other challenges to our social license to operate, our reputation could be damaged. Damage to our reputation or third-party claims initiated in response to our ongoing activities could adversely affect our continuity of operations, current and prospective business relationships, and ability to foster growth projects.

27 | CLF 2025 FORM 10-K

Table of Contents

We rely on estimates of our recoverable mineral reserves, which are complex due to geological characteristics of the properties and the number of assumptions made.

We regularly evaluate, and engage third-party QPs to review and validate, our mineral reserves based on revenues and costs and update them as required in accordance with SEC regulations. Estimates of mineral reserves and future net cash flows necessarily depend upon a number of variable factors and assumptions, some of which are beyond our control, such as production capacity, effects of governmental regulations, future prices for minerals we mine, future industry conditions and operating costs, taxes, development costs, and costs of extraction and reclamation. Estimating the quantity and grade of mineral reserves requires us to determine the size, shape and depth of our mineralized bodies by analyzing geological data, such as samplings of drill holes, and a QP to review and validate our determinations. Estimated mineral reserves could be affected by future industry conditions, future changes in the SEC’s mining property disclosure requirements, variation in geological conditions and ongoing mine planning. Actual volume and grade of reserves recovered, production rates, revenues on third-party sales and expenditures with respect to our reserves and production will likely vary from estimates, and if such variances are material, our cost structure and gross margins could be adversely affected.

In addition, we have announced that we are in the early stages of evaluating our Michigan and Minnesota mining properties for indicators of rare earth mineralization. It is uncertain whether we will be able to complete the requisite technical and economic studies to determine the economic potential for extraction of rare earths at our properties. Moreover, there is risk that our geological surveying and exploration activities may never result in the identification of rare earth minerals in economic concentrations at any of our mining properties.

Defects in title or loss of any access rights or leasehold or option interests in mining properties could limit our ability to mine these properties or result in significant unanticipated costs.

Many of our mining operations are conducted on properties we lease, license or for which we have easements, options or other possessory interests. We generally do not maintain title insurance on our mining properties, and certain of our land access arrangements were negotiated many years ago and have not been updated. Any title defect, inability to negotiate future access rights required by our mine plans, or the loss of any lease, license, option, easement or other possessory interest for any mining property could adversely affect our ability to access and mine any associated reserves. In addition, from time to time the rights of third parties for competing uses of adjacent, overlying or underlying lands, such as for roads, easements, public facilities or other mining activities, may result in disputes and affect our ability to operate as planned if our title is not superior or mutually acceptable arrangements cannot be negotiated. Any challenge to or inability to establish our title or access could delay the exploration and development of some reserves, resources, deposits or surface rights, cause us to incur unanticipated costs, and could ultimately result in the loss of some or all of our interest in those properties. In the event we lose reserves, resources, deposits or surface rights, we may be required to shut down or significantly alter impacted mining operations, thereby affecting future production, internal supply patterns and margins, revenues and cash flows.

VI. HUMAN CAPITAL RISKS

We depend on our senior management team and other key employees, and the loss of these employees could adversely affect our businesses.

Our success depends in part on our ability to attract, retain, develop and motivate our senior management and key employees. Achieving this objective may be difficult due to a variety of factors, including fluctuations in global economic and industry conditions, competitors’ hiring practices, cost reduction activities, and the effectiveness of our compensation programs. Competition for qualified personnel can be intense. We must continue to recruit, retain, develop and motivate our senior management and key personnel to maintain our businesses and support our projects. A loss of senior management and key personnel could prevent us from capitalizing on business opportunities, and our operating results could be adversely affected.

Our profitability could be adversely affected if we fail to maintain satisfactory labor relations.

Our production is dependent upon the efforts of our employees. We are party to labor agreements with various labor unions that represent employees at most of our operations. Such labor agreements are negotiated periodically, and, therefore, we are subject to the risk that these agreements may not be able to be renewed on reasonably satisfactory terms. It is difficult to predict what issues may arise as part of the collective bargaining process, and whether negotiations concerning these issues will be successful. Due to union activities or other employee actions, we could experience labor disputes, work stoppages or other disruptions in our production that could affect us adversely. Although we successfully negotiated all of our labor agreements that expired in 2025, we have other labor agreements that will expire in 2026, including those covering union workers at our Burns Harbor, Cleveland, Coatesville, Columbus Coatings, Coshocton, Indiana Harbor and Mansfield steelmaking operations, our Toledo HBI production operation and our Warren cokemaking operation, as well as all of our iron ore mining operations, and the outcomes of those labor negotiations are uncertain. If we enter into a new labor agreement with any union that significantly increases our labor costs relative to our competitors or fail to come to an agreement upon expiry, our ability to compete or continuity of production may be materially and adversely affected.

28 | CLF 2025 FORM 10-K

Table of Contents

Our expenditures for pension and OPEB obligations could be materially higher than we have predicted if our underlying assumptions differ from actual outcomes, there are regulatory changes or the funded status of the multiemployer plans that we participate in degrade.

We provide retiree benefits through defined benefit pension and OPEB plans to certain eligible employees and retirees. Certain defined benefit pension plans are underfunded and may be subject to minimum cash contributions required by ERISA. Certain OPEB plans have funding requirements that are set under our collective bargaining agreements. Our funding obligations can significantly increase if plan assets underperform, the interest rates used to calculate minimum funding levels decrease, there are changes in laws and regulations affecting funding requirements or if there are increases to the benefit obligations. The calculation of the benefit obligation is based on several assumptions, including discount rates, healthcare trend rates, benefit levels pursuant to collective bargaining, mortality and other demographic assumptions. We have seen significant changes in retiree healthcare costs in recent years, which can be affected by changes in laws and regulations. If our assumptions do not materialize as expected and we make adverse changes to these assumptions, our earnings and cash flows could be unfavorably impacted.

We also contribute to certain multiemployer pension plans, including the Steelworkers’ Pension Trust, for which we are one of the largest contributing employers. Contribution amounts are determined during collective bargaining with our unions and could increase during future collective bargaining negotiations. Our obligations to these multiemployer plans could also increase if the funded status were to decline, which could be due to poor plan asset performance or if other contributors do not meet their obligations. If a multiemployer plan were to terminate or if we choose to withdraw, we could be subject to a liability based on the plan's underfunded status.

In addition, some of the transactions in which we previously sold or otherwise disposed of our non-core assets included the assumption of certain pension and other liabilities by the purchasers or acquirers of those assets. While we believe that all such assumptions were completed properly and are legally binding, if the purchaser fails to fulfill its obligations, we may be at risk that a court, arbitrator or regulatory body could disagree and determine that we nonetheless remain responsible for such pension and other liabilities. For example, during 2025, the trustees of the United Mine Workers of America 1974 Pension Plan assessed withdrawal liability against us in respect of the Pinnacle, West Virginia and Oak Grove, Alabama coal mines that we divested in 2015. Although we do not believe that this purported withdrawal liability has been validly assessed, if the ongoing legal proceedings are determined adversely to us, then we could be required to continue making certain long-term periodic payments into the pension fund, which would adversely impact our liquidity and cash flows for an extended period of time.

We may encounter labor shortages for critical operational positions, which could adversely affect our ability to produce our products.

We are predicting a long-term shortage of skilled workers in heavy industry, such as electricians, and in certain highly specialized IT roles, such as legacy systems support, and competition for available workers limits our ability to attract and retain employees as well as engage third-party contractors. We may face potential labor shortages, as many of our most specialized and skilled roles are held by our more senior, experienced employees. As we lose these employees through attrition or otherwise, we may lose these workers’ specialized institutional knowledge of our legacy businesses and systems, and we may have difficulty replacing them at competitive wages or at all.

ITEM 7. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

Management's Discussion and Analysis of Financial Condition and Results of Operations is designed to provide a reader of our financial statements with a narrative from the perspective of management on our financial condition, results of operations, liquidity and other factors that may affect our future results. The following discussion should be read in conjunction with the consolidated financial statements and related notes that appear in Part II – Item 8. Financial Statements and Supplementary Data of this Annual Report on Form 10-K. During the third quarter of 2025, we identified an immaterial error related to our accrual for certain employment costs, resulting in an understatement of Costs of goods sold in prior periods. Prior periods affected include the interim periods ended March 31, 2025 and June 30, 2025, and the interim and annual periods during the years 2022, 2023 and 2024. Refer to NOTE 1 - BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES for further information.

Management's Discussion and Analysis of Financial Condition and Results of Operations included in this report discusses our financial condition and results of operations as of and for the years ended December 31, 2025 and 2024. A discussion related to our financial condition and results of operations for 2024 as compared to 2023 can be found in Part II - Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations of our Annual Report on Form 10-K for the year ended December 31, 2024, filed with the SEC on February 25, 2025.

OVERVIEW

Throughout 2025, we continued to position the Company for long-term success and further established ourselves as a leading North America based steel producer, particularly for the automotive industry. We announced a potential strategic partnership with a top-ten global steel producer, optimized our operational footprint, moved away from non-core assets, signed multi-year fixed price contracts with major automotive customers and further reduced unit costs year-over-year. The operational changes to our footprint, along with our commercial and strategic initiatives, further strengthen our position as a North American leader in the steel industry and are expected to create value for all Company stakeholders.

2025 HIGHLIGHTS

• Record safety year since becoming a steel company with lowest Total Recordable Incident Rate (including contractors) of 0.8 per 200,000 hours worked, which represents a 43% decrease since 2021, our first full-year as a steel company.

• President Trump implemented 50% tariffs on imported steel from all major steel producing countries and 25% on imports of automobiles and certain automobile parts.

• Signed Memorandum of Understanding with POSCO, Korea's largest steelmaker, and the world's third largest steelmaker outside of China, to potentially form a strategic partnership as POSCO seeks to leverage our domestic operations.

• Optimized operational footprint and repositioned away from non-core assets, with minimal impact to our flat-rolled steel output.

• Signed multi-year fixed price contracts with major automotive customers, increasing our market share and securing historically high-margin business for years to come.

• Improved balance sheet flexibility and capital structure by extending all senior note maturities to 2029 and beyond.

• Successfully completed a production trial in collaboration with a major automotive OEM, in which our steel was stamped into exposed automotive steel parts with no defects using the customer's existing aluminum-forming equipment.

• Further reduced unit costs year-over-year.

• Announced commissioning of our new state-of-the-art bright anneal line at our Coshocton facility.

• Five-year contract that was initiated in conjunction with the closing of the AM USA Transaction to supply approximately 1.5 million net tons of semi-finished steel slabs annually, which was unprofitable in 2024 and 2025, expired on December 9, 2025 and was not renewed.

• Maintained disciplined capital spend with 19% reduction in capital expenditures year-over-year.

ECONOMIC OVERVIEW

STEEL MARKET OVERVIEW

Steel market conditions in 2025 were driven by higher-than-historical HRC pricing and lower import levels, but subdued demand remained, driven by inconsistent buying behavior as our largest end markets experienced recession-like conditions. The price for domestic HRC, the most significant index impacting our revenues and profitability, averaged $851 per net ton for 2025, which was 10% higher than 2024. Finished steel import levels declined in 2025 after being elevated in early 2025 in anticipation of the implemented steel tariffs, which helped support domestic steel pricing. North American light vehicle production of 15.3 million units in 2025 was down from 15.4 million units in 2024 and remained lower than the five-year pre-COVID level of approximately 17 million units. Looking forward, we expect domestic steel demand to grow as interest rates have started to decline, steel imports are

43 | CLF 2025 FORM 10-K

Table of Contents

currently unattractive, other end-user demand is improving, and incremental steel demand stimulated by recent government legislation and manufacturing on-shoring is realized. Steel and light vehicles remain at the top of the Trump administration's trade agenda, and we are at the intersection of both of these industries.

We believe that steel tariffs play a crucial role in protecting the U.S. economy, national security and industrial base from violators of fair trade. The steel industry has long faced significant challenges due to overcapacity and overproduction of steel beyond certain countries' domestic needs, along with other unfair trade practices. The overproduction by certain countries results in dumping of steel in the U.S. at below market value. The U.S. remains the only major steel-producing country that produces less steel than it consumes. Additionally, foreign steel producers often take advantage of government subsidies, currency manipulation and weak environmental and safety regulations. Furthermore, there is an overall lack of foreign countries holding their own steel producers accountable for unfair trade practices. During 2025, President Trump signed an executive order to implement 50% tariffs on steel imports originating from all major steel producing countries. We believe that the 50% steel tariffs are critical to leveling the playing field and addressing global overproduction issues, confronting unfair trade practices and supporting a healthy domestic steel market. As a leading domestic steel producer, we expect to benefit for years to come from President Trump's pro-manufacturing and America-first agenda, along with the implemented tariffs, not only for steel but also for the automotive industry.

The Canadian steel industry is also an important market for us. Similar to the U.S. steel market, the Canadian steel market is impacted by global overcapacity and other unfair trade practices, resulting in the dumping of steel in Canada at below market value. This contributed to weakened results for our Canadian operations in 2025. In the second half of 2025, Canada imposed tariff-rate quotas on steel imports to protect their domestic steel industry. We expect these tariff-rate quotas to help support a healthier Canadian steel industry and allow Stelco to generate healthier margins in 2026. We believe it is crucial for Canada to maintain or improve measures in place to protect its domestic steel industry in order to preserve the Canadian economy and national security.

During 2025, to appropriately respond to market conditions and to optimize our footprint, we made the decision to fully or partially idle, or permanently close, six of our operations. These operational changes allowed us to streamline our operations and enhance efficiency, with minimal expected impact to our flat-rolled steel output.

OTHER KEY DRIVERS

The largest market for our steel products is the automotive industry in North America, which makes light vehicle production a key driver of demand. Light vehicle production in 2025 remained below the five-year pre-COVID level of approximately 17 million units. North American light vehicle production in 2025 was 15.3 million units, down from 15.4 million units in 2024. During 2025, there were 16.3 million light vehicles sold in the U.S., representing a 2% increase compared to 2024. The average age of light vehicles on the road in the U.S. is at an all-time high of 12.8 years, surpassing the previous record set in 2024, which should support demand as older vehicles need to be replaced. Furthermore, we expect the 25% tariff on imports of automobiles and certain automobile parts, which were implemented during 2025, to lead to increased demand for domestically produced vehicles that consume domestically made steel. We also expect that a declining interest rate environment would increase demand for vehicles in the U.S. as consumers have been cautious due to elevated interest rates. As a leading supplier of automotive-grade steel in the U.S., we expect to benefit from healthier domestic vehicle production over the coming years as we continue to be an established and reliable supplier.

Since 2021, the price for busheling scrap, a necessary input for flat-rolled steel production in EAFs in the U.S., has continued to average well above the prior annual ten-year average of approximately $385 per long ton. The busheling price averaged $424 per long ton during 2025. We expect the supply of busheling scrap to further tighten due to decreasing prime scrap generation from original equipment manufacturers and the growth of EAF capacity in the U.S., reduced metallics import availability, and a push for expanded scrap use globally. As we are fully integrated and have primarily a blast furnace footprint, increased prices for busheling scrap in the U.S. bolster our competitive advantage, as we source the majority of our iron feedstock from our stable-cost mining and pelletizing operations in Michigan and Minnesota.

During 2025, we continued our cost-cutting efforts, which began in 2023. We further reduced our year-over-year cost per ton as we worked through higher cost inventory, and we experienced lower coal and alloy costs, which helped mitigate the inflationary cost increases we experienced. We expect to continue our cost-cutting efforts in 2026 and maintain a strong focus on cost discipline for the long term.

44 | CLF 2025 FORM 10-K

Table of Contents

STEELMAKING RESULTS

COMPARISON OF 2025 TO 2024

The following is a summary of the Steelmaking segment operating results, net of intersegment eliminations, for the years ended December 31, 2025 and 2024 (dollars in millions, except for average selling price and shipments in thousands of net tons):

Total Revenue

Gross Margin

Adjusted EBITDA

Steel Shipments (nt)

STEEL PRODUCT REVENUE:

GROSS MARGIN %:

ADJUSTED EBITDA %:

AVERAGE SELLING PRICE PER TON OF STEEL PRODUCTS:

REVENUE

The following tables represent our steel shipments by product and total revenues by market:

Year Ended December 31,

(In thousands of net tons)

% Change

Steel shipments by product:

Hot-rolled steel

Cold-rolled steel

Coated steel

Stainless and electrical steel

Plate

Slab and other steel products

Total steel shipments

Year Ended December 31,

(In millions)

% Change

Steelmaking revenues by market:

Direct automotive

Infrastructure and manufacturing

Distributors and converters

Steel producers

Total Steelmaking revenues

Revenues from our Steelmaking segment decreased by $576 million, or 3%, during the year ended December 31, 2025, as compared to the prior year, primarily due to:

• A decrease in revenues driven by lower realized revenue rates, predominantly due to product mix (approximately $400 million);

• A decrease in revenues driven by inconsistent buying behavior from automotive, service centers and other customers resulting in lower tons sold (approximately $1.2 billion); and

• A decrease in revenues driven by permanent closures of the Steelton and Weirton operations due to financial underperformance (approximately $220 million); which was partially offset by

45 | CLF 2025 FORM 10-K

Table of Contents

• An increase in revenues related to incremental tons sold related to the addition of Stelco, which primarily consists of hot-rolled steel (approximately $1.5 billion).

GROSS MARGIN

Gross margin from our Steelmaking segment decreased by $922 million during the year ended December 31, 2025, as compared to the prior year, primarily due to:

• Lower revenues of $576 million as described above;

• An increase in depreciation and amortization expense as a result of the indefinite idling of our Conshohocken and Riverdale facilities and the Stelco Acquisition (approximately $300 million); and

• An increase in idled facilities charges as a result of the operational adjustments related to our Hibbing, Minorca and Dearborn facilities (approximately $70 million).

ADJUSTED EBITDA

Adjusted EBITDA from our Steelmaking segment for the year ended December 31, 2025, decreased by $736 million, as compared to 2024, due to the decreased financial performance from our Steelmaking operations. Additionally, our Steelmaking Adjusted EBITDA included $515 million and $457 million of Selling, general and administrative expenses for the years ended December 31, 2025 and 2024, respectively.

CONSOLIDATED RESULTS

COMPARISON OF 2025 TO 2024

REVENUES AND GROSS MARGIN

During the year ended December 31, 2025, our consolidated Revenues decreased by $575 million, as compared to 2024. The decrease was primarily due to the decrease in the average steel product selling price of $76 per net ton as a result of product mix from our Steelmaking segment.

During the year ended December 31, 2025, our consolidated gross margin decreased by $923 million, as compared to 2024. See “— Steelmaking Results” above for further detail on our operating results.

SELLING, GENERAL AND ADMINISTRATIVE EXPENSES

Selling, general and administrative expenses increased by $57 million for the year ended December 31, 2025 compared to 2024, primarily driven by a full year of Stelco selling, general, and administrative expenses resulting in an approximately $70 million increase, which was partially offset by cost-reduction initiatives implemented in 2025.

RESTRUCTURING AND OTHER CHARGES & ASSET IMPAIRMENT

As a result of decisions to indefinitely idle two non-core Steelmaking operations, the Company recorded Restructuring and other charges and Asset impairment during 2025 and 2024. The indefinite idling of the Steelton rail production facility occurred in the second quarter of 2025, while the idling of the Weirton tinplate production facility was announced in the first quarter of 2024.

Restructuring and other charges totaled $86 million for the year ended December 31, 2025, compared to $129 million for the year ended December 31, 2024. Asset impairment totaled $39 million in 2025, compared to $79 million in 2024. Refer to NOTE 2 - SUPPLEMENTARY FINANCIAL STATEMENT INFORMATION for further information.

ACQUISITION-RELATED COSTS

Acquisition-related costs decreased by $43 million during the year ended December 31, 2025 compared to 2024, primarily reflecting the absence in 2025 of significant third-party costs that were incurred in 2024 in connection with the Stelco Acquisition. Refer to NOTE 3 - ACQUISITIONS for further information.

MISCELLANEOUS – NET

Miscellaneous – net decreased by $38 million for the year ended December 31, 2025 compared to 2024. The decrease resulted from approximately $60 million improvement in currency exchange year-over-year and approximately $10 million gain from the sale of FPT Florida, along with various other improvements not individually significant. These favorable impacts were partially offset by approximately $40 million in charges for idle facilities and severance.

INTEREST EXPENSE, NET

During the year ended December 31, 2025, consolidated Interest expense, net increased by $224 million compared to 2024, primarily reflecting higher-than-average borrowing during 2025 following the Stelco Acquisition, which was completed in the fourth quarter of 2024.

46 | CLF 2025 FORM 10-K

Table of Contents

LOSS ON EXTINGUISHMENT OF DEBT

During the year ended December 31, 2025, our consolidated Loss on extinguishment of debt decreased by $17 million compared to 2024. During 2025, we redeemed an aggregate principal amount of $685 million in outstanding debt, compared to $829 million in aggregate principal amount repurch ased during 2024. The decrease in loss recorded in 2025 is primarily reflecting a lower redemption price and the related write-off of deferred charges in comparison to the prior year. Refer to NOTE 8 - DEBT AND CREDIT FACILITIES for further information.

NET PERIODIC BENEFIT CREDITS OTHER THAN SERVICE COST COMPONENT

During the year ended December 31, 2025, our consolidated Net periodic benefit credits other than service cost component decreased $24 million compared to 2024. This decrease primarily relates to an approximately $15 million year-over-year decline in amounts recognized from Accumulated other comprehensive income, largely driven by a reduction in actuarial gains and from a $5 million increase in special termination charges recorded in relation to decisions to indefinitely idle facilities in each respective period. Refer to NOTE 9 - PENSIONS AND OTHER POSTRETIREMENT BENEFITS for further information.

CHANGES IN FAIR VALUE OF DERIVATIVES, NET

During the year ended December 31, 2025, our consolidated Changes in fair value of derivatives, net increased by $4 million compared to 2024. The increase is primarily a reflection of a full year of fair value adjustments to the MinnTac option, partially offset by a one-time loss recorded on foreign currency contracts obtained in connection with financing the Stelco Acquisition in 2024. Refer to NOTE 14 - FAIR VALUE OF FINANCIAL INSTRUMENTS and NOTE 15 - DERIVATIVE INSTRUMENTS AND HEDGING for further information.

INCOME TAXES

Our effective tax rate is impacted by state income taxes and permanent items. It also is affected by discrete items that may occur in any given period but are not consistent from period to period. The following represents a summary of our tax provision and corresponding effective rates:

Year Ended December 31,

(In millions)

Income tax benefit

Effective tax rate

A reconciliation of our income tax attributable to continuing operations compared to the U.S. federal statutory rate is as follows:

Year Ended December 31,

(In millions)

Tax at U.S. statutory rate

Increase (decrease) due to:

Percentage depletion in excess of cost depletion

Unrecognized tax benefits

State taxes, net

Federal & state provision to return

Income not subject to tax

Other items, net

Provision for income tax benefit and effective income tax rate including discrete items

See NOTE 11 - INCOME TAXES for further information.

CASH FLOW, LIQUIDITY AND CAPITAL RESOURCES

OVERVIEW

Our capital allocation decision-making process is focused on preserving healthy liquidity levels, strengthening our balance sheet, and creating financial flexibility to manage through the cyclical demand for our products and volatility in commodity prices. We are focused on maximizing the cash generation of our operations, reducing debt, returning capital to shareholders, and aligning capital investments with our strategic priorities and the requirements of our business plan, including regulatory and permission-to-operate related projects.

47 | CLF 2025 FORM 10-K

Table of Contents

The following table provides a summary of our cash flow:

Year Ended December 31,

(In millions)

Cash flows provided by (used in):

Operating activities

Investing activities

Financing activities

Net increase (decrease) in cash and cash equivalents

CASH FLOWS

OPERATING ACTIVITIES

Year Ended December 31,

(In millions)

Variance

Net loss

Non-cash adjustments to net loss

Income taxes

Pension and OPEB payments and contributions

Working capital (receivables, inventories, payables and other liabilities)

Net cash provided (used) by operating activities

The variance was driven by:

• A $989 million decrease in net income after adjustments for non-cash items due to lower gross margins resulting from a decrease in selling prices for our steel products. See "— Steelmaking Results" above for further detail on our operating results.

• A $351 million increase in cash provided by working capital is primarily related to a reduction in iron ore pellet inventory in comparison to the build of iron ore pellet inventory in the prior year and is also related to a reduction in payables due to cost-cutting efforts. These increases were partially offset by a decrease in accounts receivable collections year over year as a result of lower total revenue.

INVESTING ACTIVITIES

Year Ended December 31,

(In millions)

Variance

Purchase of property, plant and equipment

Acquisitions, net of cash acquired

Proceeds from sale of business

Other 1

Net cash used by investing activities

1 Includes DOE funding associated with awarded capital projects. Refer to NOTE 1 - BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES for further information on accounting treatment on government grants.

The variance was driven by:

• A $2.5 billion decrease in cash used for acquisitions, net of cash acquired related to the Stelco Acquisition, which was completed on November 1, 2024. Refer to NOTE 3 - ACQUISITIONS for further information.

• A $134 million decrease in purchase of property, plant and equipment as a result of disciplined spending and reduction in overall sustaining capital costs primarily related to idled facilities.

• A $53 million increase in proceeds from sale of business related to the sale of FPT Florida in the fourth quarter of 2025.

48 | CLF 2025 FORM 10-K

Table of Contents

FINANCING ACTIVITIES

Year Ended December 31,

(In millions)

Variance

Net borrowings of debt

Net borrowings (repayments) under credit facilities

Net issuance (repurchase) of common shares

Other

Net cash provided by financing activities

During 2025, we completed multiple financing transactions in order to extend our debt maturities, opportunistically access the equity market and reduce the outstanding borrowings under our variable-rate ABL Facility. These transactions improved our liquidity position, reduced our sensitivity to interest rate volatility, and enhanced the overall stability of our capital structure. In comparison, our net cash provided by financing activities in 2024 was primarily a result of transactions to finance the Stelco Acquisition. Our financing transactions during 2025 were as follows:

• In February 2025, we issued $850 million aggregate principal amount of 7.500% Senior Notes due 2031 and used the proceeds primarily to repay borrowings under our ABL Facility.

• In September 2025 and October 2025, we issued $1,125 million in aggregate principal amount of 7.625% Senior Notes due 2034 and used the proceeds to redeem all then-remaining 2027 senior notes and repay borrowings under our ABL Facility.

• On October 30, 2025, we issued 75 million of our common shares in an underwritten offering, resulting in net cash proceeds of $951 million, which were subsequently used to repay borrowings under our ABL Facility.

LIQUIDITY AND CAPITAL RESOURCES

Our primary sources of liquidity are Cash and cash equivalents, cash generated from our operations, availability under our ABL Facility and access to the capital markets. Cash and cash equivalents, which totaled $57 million as of December 31, 2025, include cash on hand and on deposit, as well as short-term securities held for the primary purpose of general liquidity. The combination of cash and availability under our ABL Facility equated to $3.3 billion in liquidity as of December 31, 2025. During 2025, we issued $850 million in aggregate principal amount of our 7.500% 2031 Senior Notes and $1,125 million in aggregate principal amount of our 7.625% 2034 Senior Notes, as well as 75 million of our common shares resulting in $951 million of net cash proceeds. In totality, we used the proceeds from these transactions to extend debt maturities by redeeming all remaining 2027 senior notes and repay borrowings on our ABL Facility. We believe our liquidity and access to capital markets will be adequate to fund our cash requirements for the next 12 months and for the foreseeable future.

Our ABL Facility, which matures in June 2028, has a maximum borrowing base of $4.75 billion. The available borrowing base, which was $3.2 billion as of December 31, 2025, is determined by applying customary advance rates to eligible accounts receivable, inventory and certain mobile equipment. Our ABL Facility includes a $555 million sublimit for the issuance of letters of credit and a $200 million sublimit for swingline loans. As of December 31, 2025, outstanding letters of credit totaled $65 million, which reduced availability under our ABL Facility. We issue standby letters of credit with certain financial institutions in order to support business obligations, including, but not limited to, workers' compensation, operating agreements, employee severance, environmental obligations and insurance. Our ABL Facility agreement contains various financial and other covenants. As of December 31, 2025, we were in compliance with all of our ABL Facility covenants.

We have the capability to issue additional unsecured notes and, subject to the limitations set forth in our existing senior notes indentures and ABL Facility, additional secured notes if we elect to access the debt capital markets. We currently have approximately $3.2 billion of secured note capacity. However, our ability to issue additional notes could be limited by market conditions. We intend from time to time to seek to redeem or repurchase our outstanding senior notes with cash on hand, borrowings from existing credit sources or new debt or equity financings and/or exchanges for debt or equity securities, in open market purchases, privately negotiated transactions or otherwise. Such redemptions or repurchases, if any, will depend on prevailing market conditions, our liquidity requirements, contractual restrictions and other factors, and the amounts involved may be material.

Refer to NOTE 8 - DEBT AND CREDIT FACILITIES for further information on our ABL Facility and debt.

MATERIAL CASH REQUIREMENTS

We have material cash requirements for known contractual obligations and commitments for the following:

CAPITAL EXPENDITURES

We anticipate total cash used for capital expenditures during the next 12 months to be approximately $700 million, which primarily consists of sustaining capital spend.

49 | CLF 2025 FORM 10-K

Table of Contents

DEBT

As of December 31, 2025, our Long-term debt was $7.3 billion, with our ABL Facility maturing in 2028 and senior notes maturities starting in 2029. Refer to NOTE 8 - DEBT AND CREDIT FACILITIES for further information on our long-term debt and interest expense.

LEASE OBLIGATIONS

We have future minimum lease payments under noncancellable finance and operating leases. As of December 31, 2025, the current and non-current liabilities for our lease obligations were $115 million and $569 million, respectively. Refer to NOTE 12 - LEASE OBLIGATIONS for further information.

POST-RETIREMENT EMPLOYEE BENEFITS

We make both required and discretionary pension contributions. Required contributions are based on minimum funding requirements pursuant to ERISA regulations. We expect to make $43 million in pension contributions and payments in 2026, which is down from $68 million in 2025. The cash requirements for our OPEB plans consist of VEBA contributions and direct payments from corporate assets primarily for medical and drug costs. We expect to make $83 million in OPEB contributions and net payments from corporate assets in 2026, which is down from $86 million in 2025. Contributions and payments in future years can significantly change and will depend on the actual returns on assets, discount rates, actual health care trend rates, government regulations, changes to employee benefits through labor agreements and other demographic factors. Refer to NOTE 9 - PENSIONS AND OTHER POSTRETIREMENT BENEFITS for further information.

ENVIRONMENTAL AND ASSET RETIREMENT OBLIGATIONS

Refer to NOTE 13 - ASSET RETIREMENT AND ENVIRONMENTAL OBLIGATIONS for further information on our environmental and asset retirement obligations.

SHARE REPURCHASE PROGRAM

On April 22, 2024, our Board of Directors authorized a program to repurchase our outstanding common shares in the open market or in privately negotiated transactions, which may include purchases pursuant to Rule 10b5-1 plans or accelerated share repurchases, up to a maximum of $1.5 billion. We are not obligated to make any repurchases, and the program may be suspended or discontinued at any time. The share repurchase program does not have a specific expiration date. As of December 31, 2025, there was $1.4 billion remaining authorization under the share repurchase program.

OFF-BALANCE SHEET ARRANGEMENTS

In the normal course of business, we are a party to certain off-balance sheet arrangements that are not reflected on our Statements of Consolidated Financial Position. These arrangements include unconditional purchase obligations, surety bonds and letters of credit. Our unconditional purchase obligations include minimum "take or pay" commitments, such as minimum electric power demand charges, minimum coal, coke, diesel, industrial gas and natural gas purchase commitments, minimum railroad transportation commitments and minimum port facility usage commitments.

We use surety bonds and letters of credit to provide financial assurance for certain obligations. As of December 31, 2025, we had $278 million of outstanding surety bonds and surety-backed letters of credit. The use of surety bonds and surety-backed letters of credit has no impact on our liquidity. Additionally, as of December 31, 2025, we had $65 million of outstanding letters of credit issued under our ABL Facility, which reduced our availability thereunder.

Refer to NOTE 20 - COMMITMENTS AND CONTINGENCIES for further information on our unconditional purchase obligations, surety bonds and surety-backed letters of credit.

NON-GAAP FINANCIAL MEASURE

The following provides a description and reconciliation of our non-GAAP financial measure to its most directly comparable GAAP measure. The presentation of this measure is not intended to be considered in isolation from, as a substitute for, or as superior to, the financial information prepared and presented in accordance with GAAP. The presentation of this measure may be different from non-GAAP financial measures used by other companies.

ADJUSTED EBITDA

We evaluate performance on an operating segment basis, as well as a consolidated basis, based on Adjusted EBITDA, which is a non-GAAP measure. This measure is used by management, investors, lenders and other external users of our financial statements to assess our operating performance and to compare operating performance to other companies in the steel industry. In addition, management believes Adjusted EBITDA is a useful measure to assess the earnings power of the business without the impact of capital structure and can be used to assess our ability to service debt and fund future capital expenditures in the business.

50 | CLF 2025 FORM 10-K

Table of Contents

The following table provides a reconciliation of our Net income (loss) to Adjusted EBITDA:

Year Ended December 31,

(In millions)

Net income (loss)

Less:

Interest expense, net

Income tax benefit (expense)

Depreciation, depletion and amortization

Total EBITDA

Less:

EBITDA from noncontrolling interests 1

Idled facilities charges

Changes in fair value of derivatives, net

Currency exchange

Severance

Loss on extinguishment of debt

Gain on sale of business

Loss on disposal of assets

Amortization of inventory step-up

Acquisition-related costs

Goodwill impairment

Arbitration decision

Other, net

Total Adjusted EBITDA

1 EBITDA of noncontrolling interests includes the following:

Net income attributable to noncontrolling interests

Depreciation, depletion and amortization

EBITDA of noncontrolling interests

The following table provides a summary of our Adjusted EBITDA by segment:

Year Ended December 31,

(In millions)

Adjusted EBITDA:

Steelmaking

Other Businesses

Intersegment Eliminations

Total Adjusted EBITDA

INFORMATION ABOUT OUR GUARANTORS AND THE ISSUER OF OUR GUARANTEED SECURITIES

The accompanying summarized financial information has been prepared and presented pursuant to SEC Regulation S-X, Rule 3-10, “Financial Statements of Guarantors and Issuers of Guaranteed Securities Registered or Being Registered,” and Rule 13-01 "Financial Disclosures about Guarantors and Issuers of Guaranteed Securities and Affiliates Whose Securities Collateralized a Registrant's Securities." Certain of our subsidiaries (the "Guarantor subsidiaries") as of December 31, 2025 have fully and unconditionally, and jointly and severally, guaranteed the obligations under the 4.625% 2029 Senior Notes, the 6.875% 2029 Senior Notes, the 6.750% 2030 Senior Notes, the 4.875% 2031 Senior Notes, the 7.500% 2031 Senior Notes, the 7.000% 2032 Senior Notes, the 7.375% 2033 Senior Notes and the 7.625% 2034 Senior Notes issued by Cleveland-Cliffs Inc. on a senior unsecured basis. See NOTE 8 - DEBT AND CREDIT FACILITIES for further information.

The following presents the summarized financial information on a combined basis for Cleveland-Cliffs Inc. (parent company and issuer of the guaranteed obligations) and the Guarantor subsidiaries, collectively referred to as the obligated group. Transactions between the obligated group have been eliminated. Information for the non-Guarantor subsidiaries was excluded from the combined summarized financial information of the obligated group.

51 | CLF 2025 FORM 10-K

Table of Contents

Each Guarantor subsidiary is consolidated by Cleveland-Cliffs Inc. as of December 31, 2025. Refer to Exhibit 22 , incorporated herein by reference, for the detailed list of entities included within the obligated group as of December 31, 2025.

As of December 31, 2025, the guarantee of a Guarantor subsidiary with respect to the 4.625% 2029 Senior Notes, the 6.875% 2029 Senior Notes, the 6.750% 2030 Senior Notes, the 4.875% 2031 Senior Notes, the 7.500% 2031 Senior Notes, the 7.000% 2032 Senior Notes, the 7.375% 2033 Senior Notes and the 7.625% 2034 Senior Notes will be automatically and unconditionally released and discharged, and such Guarantor subsidiary’s obligations under the guarantee and the related indentures (the “Indentures”) will be automatically and unconditionally released and discharged, upon the occurrence of any of the following, along with the delivery to the trustee of an officer’s certificate and an opinion of counsel, each stating that all conditions precedent provided for in the applicable Indenture relating to the release and discharge of such Guarantor subsidiary’s guarantee have been complied with:

(a) any sale, exchange, transfer or disposition of such Guarantor subsidiary (by merger, consolidation, or the sale of) or the capital stock of such Guarantor subsidiary after which the applicable Guarantor subsidiary is no longer a subsidiary of the Company or the sale of all or substantially all of such Guarantor subsidiary’s assets (other than by lease), whether or not such Guarantor subsidiary is the surviving entity in such transaction, to a person which is not the Company or a subsidiary of the Company; provided that (i) such sale, exchange, transfer or disposition is made in compliance with the applicable Indenture, including the covenants regarding consolidation, merger and sale of assets and, as applicable, dispositions of assets that constitute notes collateral, and (ii) all the obligations of such Guarantor subsidiary under all debt of the Company or its subsidiaries terminate upon consummation of such transaction;

(b) designation of any Guarantor subsidiary as an “excluded subsidiary” (as defined in the Indentures); or

(c) defeasance or satisfaction and discharge of the Indentures.

Each entity in the summarized combined financial information follows the same accounting policies as described in the consolidated financial statements. The accompanying summarized combined financial information does not reflect investments of the obligated group in non-Guarantor subsidiaries. The financial information of the obligated group is presented on a combined basis; intercompany balances and transactions within the obligated group have been eliminated. The obligated group's amounts due from, amounts due to, and transactions with, non-Guarantor subsidiaries and related parties have been presented in separate line items.

SUMMARIZED COMBINED FINANCIAL INFORMATION OF THE ISSUER AND GUARANTOR SUBSIDIARIES

The following table is summarized combined financial information from the Statements of Condensed Consolidated Financial Position of the obligated group:

December 31,

(In millions)

Current assets

Non-current assets

Current liabilities

Non-current liabilities

The following table is summarized combined financial information from the Statements of Condensed Consolidated Operations of the obligated group:

Year Ended

(In millions)

December 31, 2025

Revenues

Cost of goods sold

Loss from continuing operations

Net loss

Net loss attributable to Cliffs shareholders

52 | CLF 2025 FORM 10-K

Table of Contents

As of December 31, 2025, the obligated group had the following balances with non-Guarantor subsidiaries and other related parties:

December 31,

(In millions)

Balances with non-Guarantor subsidiaries:

Accounts receivable, net

Accounts payable

Balances with other related parties:

Accounts receivable, net

Accounts payable

Additionally, for the year ended December 31, 2025, the obligated group had Revenues of $84 million and Cost of goods sold of $73 million, in each case with other related parties.

MARKET RISKS

We are subject to a variety of risks, including those caused by changes in commodity prices and interest rates. We have established policies and procedures to manage such risks; however, certain risks are beyond our control.

PRICING RISKS

In the ordinary course of business, we are exposed to price fluctuations in both the production and sale of our products. Price fluctuations related to the production of our products are impacted by market prices for natural gas, electricity, ferrous and stainless steel scrap, metallurgical coal, coke, zinc, chrome, nickel and other alloys. Price fluctuations related to the sale of our products are primarily impacted by market prices for HRC and other related spot indices. Our financial results can vary for our operations as a result of these fluctuations.

Our strategy to address the risk of changes in the prices of both energy and raw materials that are purchased and utilized in our operations includes improving efficiency in energy usage, identifying alternative providers, utilizing the lowest cost alternative fuels and making forward physical purchases.

Some customer contracts have fixed pricing terms, which increase our exposure to fluctuations in raw material and energy costs. To reduce our exposure, we enter into annual, fixed price agreements for certain raw materials. Some of our existing multi-year raw material supply agreements have required minimum purchase quantities. Under adverse economic conditions, those minimums may exceed our needs. Absent exceptions for force majeure and other circumstances affecting the legal enforceability of the agreements, these minimum purchase requirements may compel us to purchase quantities of raw materials that could significantly exceed our anticipated needs or pay damages to the supplier for shortfalls. In these circumstances, we would attempt to negotiate agreements for new purchase quantities. There is a risk, however, that we would not be successful in reducing purchase quantities, either through negotiation or litigation. If that occurred, we would likely be required to purchase more of a particular raw material in a particular year than we need, negatively affecting our results of operations and cash flows.

Certain of our customer contracts include variable-pricing mechanisms that adjust selling prices in response to changes in the costs of certain raw materials and energy, while other of our customer contracts exclude such mechanisms. We may enter into multi-year purchase agreements for certain raw materials with similar variable-price mechanisms, allowing us to achieve natural hedges between the customer contracts and supplier purchase agreements. Therefore, in some cases, price fluctuations for energy (particularly natural gas and electricity), raw materials (such as scrap, chrome, zinc and nickel) or other commodities may be, in part, passed on to customers rather than absorbed solely by us. There is a risk, however, that the variable-price mechanisms in the sales contracts may not necessarily change in tandem with the variable-price mechanisms in our purchase agreements, negatively affecting our results of operations and cash flows.

If we are unable to align fixed and variable components between customer contracts and supplier purchase agreements, we routinely evaluate the use of derivative instruments to hedge market risk. As a result, we use cash-settled commodity price swaps to hedge a portion of our exposure from our natural gas and electricity requirements. Our hedging strategy is designed to protect us from excessive pricing volatility. However, since we do not typically hedge 100% of our exposure, abnormal price increases in any of these commodity markets might still negatively affect operating costs.

Our strategy to address price fluctuations related to the selling price of our products has generally been to obtain competitive prices for our products and allow operating results to reflect market price movements dictated by supply and demand; however, from time to time, we also utilize sales swaps to manage our exposure to HRC price fluctuations in the average selling price of our products.

53 | CLF 2025 FORM 10-K

Table of Contents

The following table summarizes the negative effect of a hypothetical change in the fair value of our derivative instruments outstanding as of December 31, 2025, due to a 10% and 25% change in the market price of each of the indicated commodities:

(In millions)

Contract Type

10% Change

25% Change

Natural gas

Electricity

HRC

Any resulting changes in fair value would be recorded as adjustments to AOCI, net of income taxes, or recognized in net earnings, as appropriate. These hypothetical losses would be partially offset by the benefit of lower prices paid for the related commodities or the benefit of higher selling prices related to the HRC price, respectively.

VALUATION OF GOODWILL AND OTHER LONG-LIVED ASSETS

GOODWILL

We assign goodwill arising from acquired companies to the reporting units that are expected to benefit from the synergies of the acquisition. Goodwill is tested on a qualitative or quantitative basis for impairment at the reporting unit level on an annual basis (October 1) and between annual tests if a triggering event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying value. We have an unconditional option to bypass the qualitative test for any reporting unit in any period and proceed directly to performing the quantitative test. Should our qualitative test indicate that it is more likely than not that the fair value of a reporting unit is less than its carrying value, we perform a quantitative test to determine the amount of impairment, if any, to the carrying value of the reporting unit and its associated goodwill.

Triggering events could include a significant and sustained change in the business climate, including, among other factors, declines in historical or projected revenue, operating income, Adjusted EBITDA or cash flows, and declines in the stock price or market capitalization, considered both in absolute terms and relative to peers, legal factors, competition, or sale or disposition of a significant portion of a reporting unit. Automotive production and sales are cyclical and sensitive to general economic conditions and other factors, including interest rates, consumer credit, spending and preferences, and supply chain disruptions. Additionally, to the extent that commodity prices, including the HRC price, coated and other specialty steel prices, international steel prices and scrap metal prices, significantly decline for an extended period, we may have to further revise our operating plans. As a result, testing for potential impairment on our goodwill may be adversely affected by uncertain market conditions for the global steel industry, as well as changes in interest rates, inflation, commodity prices and general economic conditions. Changes in general economic and/or industry specific conditions, such as the impacts of significant recent shifts in trade policies, including the imposition of tariffs, retaliatory tariff measures and subsequent modifications or suspensions thereof, and market reactions to such policies and resulting trade disputes, could further impact our impairment assessments. We do not believe the current challenging macroeconomic and industry conditions, or volatility in our market capitalization, have significantly changed our assessment of the fair value of our reporting units.

Application of a goodwill impairment test requires judgment, including the identification of reporting units, assignment of assets and liabilities to reporting units, assignment of goodwill to reporting units, and the determination of the fair value of each reporting unit, if a quantitative assessment is deemed necessary. The fair value of each reporting unit is estimated using the guideline public company method, the discounted cash flow methodology, or a combination of both, which considers forecasted cash flows discounted at an estimated weighted average cost of capital. Assessing the recoverability of our goodwill requires significant assumptions regarding discount rates, market multiples, the estimated future cash flows and other factors to determine the fair value of a reporting unit, including, among other things, estimates related to forecasts of future revenues, Adjusted EBITDA, capital expenditures and working capital requirements, which are based upon our long-range plan estimates. The assumptions used to calculate the fair value of a reporting unit may change based on operating results, market conditions and other factors. Changes in these assumptions could materially affect the determination of fair value for each reporting unit.

No impairment charges were identified in connection with our annual goodwill impairment test with respect to our identified reporting units.

OTHER LONG-LIVED ASSETS

Long-lived assets are reviewed for impairment upon the occurrence of events or changes in circumstances that would indicate that the carrying value of the assets may not be recoverable. Such indicators may include: a significant decline in expected future cash flows; a sustained, significant decline in market pricing; a significant adverse change in legal or environmental factors or in the business climate; changes in estimates of our recoverable reserves; and unanticipated competition. Any adverse change in these factors could have a significant impact on the recoverability of our long-lived assets and could have a material impact on our consolidated statements of operations and statements of financial position.

A comparison of each asset group's carrying value to the estimated undiscounted net future cash flows expected to result from the use of the assets, including cost of disposition, is used to determine if an asset is recoverable. Projected future cash flows reflect management's best estimate of economic and market conditions over the projected period, including growth rates in revenues and costs, and estimates of future expected changes in operating margins and capital expenditures. If the carrying value of the asset group is higher than its undiscounted net future cash flows, the asset group is measured at fair value and the difference is recorded as a reduction to the long-lived assets. We estimate fair value using a market approach, an income approach or a cost approach.

54 | CLF 2025 FORM 10-K

Table of Contents

During the year ended December 31, 2025, we concluded there were no triggering events resulting in the need for an asset impairment assessment except for the announcement of the indefinite idle of our Steelton rail production plant, which resulted in a $39 million asset impairment charge.

FOREIGN CURRENCY EXCHANGE RATE RISK

We are subject to changes in foreign currency exchange rates primarily as a result of our operations in Canada, which could impact our financial condition. Foreign exchange rate risk arises from our exposure to fluctuations in foreign currency exchange rates because our reporting currency is the U.S. dollar, but the functional currency of our Stelco subsidiaries is the Canadian dollar. Specifically, we are primarily exposed to fluctuations in foreign currency rates in relation to an intercompany note with our Stelco subsidiary that is denominated in the Canadian dollar. Changes in the Canadian dollar exchange rate may result in volatility in our financial condition due to the routine remeasurement of this note. As of December 31, 2025, a 1% change in the Canadian dollar foreign currency exchange rate would result in a $9 million change in currency exchange income (expense). Additionally, we engage in routine transactions denominated in foreign currencies, such as the purchases of goods and services. However, the potential impact of these transactions to our financial condition is significantly less than the potential impact of the routine remeasurement of the intercompany note.

INTEREST RATE RISK

Interest payable on our senior notes is at fixed rates. Interest payable under our ABL Facility is at a variable rate based upon the applicable base rate plus the applicable base rate margin depending on the excess availability. As of December 31, 2025, we had $452 million outstanding borrowings under our ABL Facility. An increase in prevailing interest rates would increase interest expense and interest paid for any outstanding borrowings under our ABL Facility. For example, a 100 basis point change to interest rates under our ABL Facility at the December 31, 2025 borrowing level would result in a change of $5 million to interest expense on an annual basis. For a discussion of the attendant risk, see Part I – Item 1A. Risk Factors – III. Financial Risks – Our existing and future indebtedness may limit cash flow available to invest in the ongoing needs of our businesses, which could prevent us from fulfilling our obligations under our senior notes, ABL Facility and other debt, and we may be forced to take other actions to satisfy our obligations under our debt, which may not be successful.

SUPPLY CONCENTRATION RISKS

Many of our operations and mines rely on one source for each of electric power and natural gas. A significant interruption or change in service or rates from our energy suppliers could materially impact our production costs, margins and profitability.

RECENTLY ISSUED ACCOUNTING PRONOUNCEMENTS

Refer to NOTE 1 - BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES of the consolidated financial statements for a description of recent accounting pronouncements, including the respective dates of adoption and effects on results of operations and financial condition.

CRITICAL ACCOUNTING ESTIMATES

Management's discussion and analysis of financial condition and results of operations is based on our consolidated financial statements, which have been prepared in accordance with GAAP. Preparation of financial statements requires management to make assumptions, estimates and judgments that affect the reported amounts of assets, liabilities, revenues, costs and expenses, and the related disclosures of contingencies. Management bases its estimates on various assumptions and historical experience, which are believed to be reasonable; however, due to the inherent nature of estimates, actual results may differ significantly due to changed conditions or assumptions. On a regular basis, management reviews the accounting policies, assumptions, estimates and judgments to ensure that our financial statements are fairly presented in accordance with GAAP. However, because future events and their effects cannot be determined with certainty, actual results could differ from our assumptions and estimates, and such differences could be material. Management believes that the following critical accounting estimates and judgments have a significant impact on our financial statements.

BUSINESS COMBINATIONS

Assets acquired and liabilities assumed in a business combination are recognized and measured based on their estimated fair values at the acquisition date, while the acquisition-related costs are expensed as incurred. Any excess of the purchase consideration when compared to the fair value of the net tangible and intangible assets acquired, if any, is recorded as goodwill. We engage independent valuation specialists to assist with the determination of the fair value of assets acquired, liabilities assumed and goodwill associated with an acquisition. If the initial accounting for the business combination is incomplete by the end of the reporting period in which the acquisition occurs, an estimate will be recorded. Subsequent to the acquisition date, and not later than one year from the acquisition date, we will record any material adjustments to the initial estimate based on new information obtained that existed as of the date of the acquisition. Any adjustment that arises from information obtained that did not exist as of the date of the acquisition will be recorded in the period the adjustment arises.

VALUATION OF GOODWILL AND OTHER LONG-LIVED ASSETS

The valuation of goodwill and other long-lived assets includes various assumptions and are considered critical accounting estimates. Refer to "–Market Risks" above for additional information.

55 | CLF 2025 FORM 10-K

Table of Contents

IRON ORE MINERAL RESERVES

We regularly evaluate, and engage QPs to review and validate, our mineral reserves and update them as required in accordance with Subpart 1300 of Regulation S-K. We perform an in-depth evaluation of our mineral reserve estimates by mine on a periodic basis, in addition to routine annual assessments. The determination of mineral reserves requires us and third-party QPs to make significant estimates and assumptions related to key inputs, including, but not limited to, (1) the determination of the size and scope of the iron ore body through technical modeling, (2) the estimates of future iron ore prices, production costs and capital expenditures, and (3) management’s mine plan for the proven and probable mineral reserves. The significant estimates and assumptions could be affected by future industry conditions, geological conditions and ongoing mine planning. Additional capital and development expenditures may be required to maintain effective production capacity. Generally, as mining operations progress, haul distances increase. Alternatively, changes in economic conditions or the expected quality of mineral resources and reserves could decrease effective production capacity. Technological progress could alleviate such factors or increase capacity of mineral reserves.

We use our mineral reserve estimates, combined with our estimated annual production levels and operating scenarios, to determine the mine closure dates utilized in recording the fair value liability for asset retirement obligations for our active operating mines. Since the liability represents the present value of the expected future obligation, a significant change in mineral reserves or mine lives could have a substantial effect on the recorded obligation. We also utilize mineral reserves for evaluating potential impairments of goodwill and mine asset groups as they are indicative of future cash flows and in determining maximum useful lives utilized to calculate depreciation, depletion and amortization of long-lived mine assets. Refer to NOTE 13 - ASSET RETIREMENT AND ENVIRONMENTAL OBLIGATIONS for further information.

ASSET RETIREMENT OBLIGATIONS

Asset retirement obligations provide for contractual and legal obligations related to our indefinitely idled and closed operations and also provide for the eventual closure of our active operations. We perform an in-depth evaluation of the liability every three years in addition to our routine annual assessments. In 2023, we employed third-party specialists to assist in the evaluation. Our obligations are determined based on detailed estimates adjusted for factors that a market participant would consider (e.g., inflation, overhead and profit), which are escalated at an assumed rate of inflation to the estimated closure dates and then discounted using the current credit-adjusted risk-free interest rate. The estimate also incorporates incremental increases in the closure cost estimates and changes in estimates of mine lives for our active mine sites. The closure date for each of our active mine sites is determined based on the exhaustion date of the remaining mineral reserves, which is dependent on our estimate of mineral reserves. The estimated obligations for our active mine sites are particularly sensitive to the impact of changes in mine lives given the difference between the inflation and discount rates.

Asset retirement obligations at our steelmaking operations primarily include the closure and post-closure care for on-site landfills and other waste containment facilities. Asset retirement obligations have been recorded at present values using settlement dates based on when we expect these facilities to reach capacity and close. Changes in the base estimates of legal and contractual closure costs due to changes in legal or contractual requirements, available technology, inflation, overhead or profit rates also could have a significant impact on the recorded obligations. Refer to NOTE 13 - ASSET RETIREMENT AND ENVIRONMENTAL OBLIGATIONS for further information.

ENVIRONMENTAL REMEDIATION COSTS

We have a formal policy for environmental protection and remediation. Our obligations for known environmental matters at active and closed operations have been recognized based on estimates of the cost of investigation and remediation at each facility. If the obligation can only be estimated as a range of possible amounts, with no specific amount being more likely, the minimum of the range is accrued. Management reviews its environmental remediation sites quarterly to determine if additional cost adjustments or disclosures are required. The characteristics of environmental remediation obligations, where information concerning the nature and extent of clean-up activities is not immediately available and which are subject to changes in regulatory requirements, result in a significant risk of increase to the obligations as they mature. Expected future expenditures are discounted to present value unless the amount and timing of the cash disbursements cannot be reasonably estimated. Refer to NOTE 13 - ASSET RETIREMENT AND ENVIRONMENTAL OBLIGATIONS for further information.

INCOME TAXES

Our income tax expense, deferred tax assets and liabilities and reserves for unrecognized tax benefits reflect management's best assessment of estimated future taxes to be paid. We are subject to income taxes in the U.S. and various foreign jurisdictions. Significant judgments and estimates are required in determining the consolidated income tax expense.

Deferred income taxes arise from temporary differences between tax and financial statement recognition of revenue and expense. In evaluating our ability to recover our deferred tax assets, we consider all available positive and negative evidence, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax planning strategies and recent financial operations. In projecting future taxable income, we begin with historical results adjusted for the results of discontinued operations and changes in accounting policies and incorporate assumptions including the amount of future state, federal and foreign pre-tax operating income, the reversal of temporary differences, and the implementation of feasible and prudent tax planning strategies. These assumptions require significant judgment about the forecasts of future taxable income and are consistent with the plans and estimates we are using to manage the underlying businesses.

56 | CLF 2025 FORM 10-K

Table of Contents

As of December 31, 2025 and 2024, we had a valuation allowance of $394 million and $388 million, respectively, against our deferred tax assets. As of December 31, 2025 and 2024, the valuation allowance on our U.S. deferred tax assets was $47 million and $39 million, respectively, and the valuation allowance on our foreign deferred tax assets was $347 million and $349 million, respectively.

Our losses in Luxembourg and certain Canadian entities in recent periods represent sufficient negative evidence to require a full valuation allowance against the deferred tax assets in those jurisdictions. We intend to maintain a valuation allowance against the deferred tax assets related to the operating losses in these jurisdictions, unless and until sufficient positive evidence exists to support the realization of such assets.

Changes in tax laws and rates also could affect recorded deferred tax assets and liabilities in the future. The calculation of our tax liabilities involves dealing with uncertainties in the application of complex tax laws and regulations in various jurisdictions across our global operations. The ultimate impact of U.S. income tax reform legislation may differ from our current estimates due to changes in the interpretations and assumptions made as well as additional regulatory guidance that may be issued.

Accounting for uncertainty in income taxes recognized in the financial statements requires that a tax benefit from an uncertain tax position be recognized when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, based on technical merits.

We recognize tax liabilities in accordance with ASC 740, Income Taxes , and we adjust these liabilities when our judgment changes because of evaluation of new information not previously available. Due to the complexity of some of these uncertainties, the ultimate resolution may result in payment that is materially different from our current estimate of the tax liabilities. These differences will be reflected as increases or decreases to income tax expense in the period in which they are determined. Refer to NOTE 11 - INCOME TAXES for further information.

EMPLOYEE RETIREMENT BENEFIT OBLIGATIONS

We sponsor various defined benefit pension plans and OPEB plans for certain current employees and retirees. For accounting purposes, we use various actuarial assumptions and methodologies to measure the plan obligations, assets and related net periodic benefit cost or credit at the end of each year. These assumptions include discount rates, expected return on plan assets, mortality rates, rates of compensation increase, healthcare trend rates and certain demographic assumptions. Assumptions and calculations are reviewed by management and reflect our best estimates and judgment. Future changes in assumptions or differences between actual and expected can significantly impact the future funded status of our plans as well as their related net periodic benefit cost or credit.

We believe discount rates and expected return on assets are the most critical assumptions. The discount rates used to measure plan liabilities as of the December 31 measurement date are determined individually for each plan. The discount rates are determined by matching the projected cash flows used to determine the plan liabilities to a projected yield curve of high-quality corporate bonds available at the measurement date. Discount rates for expense are calculated using the granular approach for each plan.

The expected return on plan assets are calculated on a plan-by-plan basis and take into account each plan's strategic asset allocation. The calculation of rates by asset class are based primarily on our future expected returns and take into consideration the duration of the cash flows, active management and fees. The difference between our expected return on plan assets assumptions and the actual returns are recorded in AOCI and ultimately affects future earnings in subsequent years. Although our actual returns will likely differ from our estimate on any given year, the returns over the long term are expected to match our assumptions. In 2026, our weighted average expected return on assets for pension and OPEB plans will remain at 7.85% and 5.89%, respectively.

Cumulative actuarial gains and losses will be amortized to expense using the corridor method, where gains and losses are recognized if they exceed 10% of the greater of the fair value of plan assets or the plans' benefit obligations. The amortization period will vary by plan.

The following are sensitivities of potential further changes in these key assumptions on the estimated 2026 pension and OPEB expense and the pension and OPEB obligations as of December 31, 2025:

Increase (Decrease) in Expense

Increase in Benefit Obligation

(In millions)

Pension

OPEB

Pension

OPEB

Decrease discount rate 0.25%

Decrease return on assets 1.00%

Refer to NOTE 9 - PENSIONS AND OTHER POSTRETIREMENT BENEFITS for further information.

57 | CLF 2025 FORM 10-K

Table of Contents

FORWARD-LOOKING STATEMENTS

This report contains statements that constitute "forward-looking statements" within the meaning of the federal securities laws. As a general matter, forward-looking statements relate to anticipated trends and expectations rather than historical matters. Forward-looking statements are subject to uncertainties and factors relating to our operations and business environment that are difficult to predict and may be beyond our control. Such uncertainties and factors may cause actual results to differ materially from those expressed or implied by the forward-looking statements. These statements speak only as of the date of this report, and we undertake no ongoing obligation, other than that imposed by law, to update these statements. Investors are cautioned not to place undue reliance on forward-looking statements. Uncertainties and risk factors that could affect our future performance and cause results to differ from the forward-looking statements in this report include, but are not limited to:

• continued volatility of steel, scrap metal and iron ore market prices, which directly and indirectly impact the prices of the products that we sell to our customers;

• uncertainties associated with the highly competitive and cyclical steel industry and our reliance on the demand for steel from the automotive industry;

• potential weaknesses and uncertainties in global economic conditions, excess global steelmaking capacity and production, prevalence of steel imports and reduced market demand;

• severe financial hardship, bankruptcy, temporary or permanent shutdowns or operational challenges of one or more of our major customers, key suppliers or contractors, which, among other adverse effects, could disrupt our operations or lead to reduced demand for our products, increased difficulty collecting receivables, and customers and/or suppliers asserting force majeure or other reasons for not performing their contractual obligations to us;

• risks related to U.S. and Canadian government actions and other countries' reactions with respect to Section 232, the USMCA and/or other trade agreements, tariffs, treaties or policies, as well as the uncertainty of obtaining and maintaining effective antidumping and countervailing duty orders to counteract the harmful effects of unfairly traded imports;

• impacts of extensive governmental regulation, including actual and potential environmental regulations relating to climate change and carbon emissions, and related costs and liabilities, including failure to receive or maintain required operating and environmental permits, approvals, modifications or other authorizations of, or from, any governmental or regulatory authority and costs related to implementing improvements to ensure compliance with regulatory changes, including potential financial assurance requirements, and reclamation and remediation obligations;

• potential impacts to the environment or exposure to hazardous substances resulting from our operations;

• our ability to maintain adequate liquidity, our level of indebtedness and the availability of capital could limit our financial flexibility and cash flow necessary to fund working capital, planned capital expenditures, acquisitions, and other general corporate purposes or ongoing needs of our business, or to repurchase our common shares;

• our ability to reduce our indebtedness or return capital to shareholders within the currently expected timeframes or at all;

• adverse changes in credit ratings, interest rates, foreign currency rates and tax laws;

• risks and uncertainties related to our ability to realize the anticipated synergies or other expected benefits of any acquisitions, including the Stelco Acquisition, any potential transaction arising out of our Memorandum of Understanding with POSCO and completing any proposed asset divestiture transactions;

• challenges to successfully implementing our business strategy to achieve operating results in line with our guidance;

• the outcome of, and costs incurred in connection with, lawsuits, claims, arbitrations or governmental proceedings relating to commercial and business disputes, antitrust claims, environmental matters, government investigations, occupational or personal injury claims, property-related matters, labor and employment matters, mineral royalty disputes, or suits involving legacy operations and other matters;

• supply chain disruptions or changes in the cost, quality or availability of energy sources, including electricity, natural gas and diesel fuel, water, critical raw materials and supplies, including iron ore, industrial gases, graphite electrodes, scrap metal, chrome, zinc, other alloys, coke and metallurgical coal, and critical manufacturing equipment and spare parts;

• problems or disruptions associated with transporting products to our customers, moving manufacturing inputs or products internally among our facilities, or suppliers transporting raw materials and spare parts to us;

• our ability to implement strategic or sustaining capital projects on time and on budget;

• uncertainties associated with natural or human-caused disasters, adverse weather conditions, unanticipated geological conditions, critical equipment failures, infectious disease outbreaks, tailings dam failures and other unexpected events;

• cybersecurity incidents relating to, disruptions in, or failures of, IT systems that are managed by us or third parties that host or have access to our data or systems, including the loss, theft or corruption of our or third parties' sensitive or essential business or personal information and the inability to access or control systems, as well as emerging risks related to the adoption and regulation of AI;

• liabilities and costs arising in connection with business decisions to temporarily or indefinitely idle or permanently close an operating facility or mine, which could adversely impact the carrying value of associated assets and give rise to

58 | CLF 2025 FORM 10-K

Table of Contents

impairment charges or closure and reclamation obligations, as well as uncertainties associated with resuming production at any previously idled operating facility or mine;

• our level of self-insurance and our ability to obtain sufficient third-party insurance to adequately cover potential adverse events and business risks;

• uncertainties associated with our ability to meet customers’ and suppliers’ decarbonization goals and reduce our emissions in alignment with our own announced targets;

• challenges to maintaining our social license to operate with our stakeholders, including the impacts of our operations on local communities, reputational impacts of operating in a carbon-intensive industry that produces GHG emissions, and our ability to foster a consistent operational and safety track record;

• our actual economic mineral reserves or reductions in current mineral reserve estimates, and any title defect or loss of any lease, license, option, easement or other possessory interest for any mining property;

• our ability to complete technical and economic studies to determine the potential for economic extraction of rare earth minerals at our mining properties, and the risk that rare-earth extraction at our properties may not be economically viable;

• our ability to maintain satisfactory labor relations with unions and our employees;

• unanticipated or higher costs associated with pension and OPEB obligations resulting from changes in the value of plan assets or contribution increases required for unfunded obligations, including for multiemployer plan withdrawal liability;

• uncertain availability or cost of skilled workers to fill critical operational positions and potential labor shortages caused by experienced employee attrition or otherwise, as well as our ability to attract, hire, develop and retain key personnel; and

• potential significant deficiencies or material weaknesses in our internal control over financial reporting.

For additional factors affecting our businesses, refer to  Part I – Item 1A. Risk Factors. You are urged to carefully consider these risk factors.

Forward-looking and other statements in this Annual Report on Form 10-K regarding our GHG reduction plans and goals are not an indication that these statements are necessarily material to investors or required to be disclosed in our filings with the SEC. Historical, current and forward-looking GHG-related statements may be based on standards for measuring progress that are still developing, internal controls and processes that continue to evolve, and assumptions that are subject to change in the future.