FISI Financial Institutions Inc - 8-K

Item 7.01 Regulation FD Disclosure.

The Company published an investor presentation with data for the first quarter ended March 31, 2026. The presentation is available on the Company’s website at www.FISI-investors.com under “Events & Presentations”. Investors should note that the Company announces material information in Securities and Exchange Commission (“SEC”) filings and press releases. Based on guidance from the SEC, the Company may also use the Investor Relations section of its corporate website, www.FISI-investors.com , to communicate with investors about the Company. It is possible that the information posted there could be deemed to be material information. The information on the Company’s website is not incorporated by reference into this Current Report on Form 8-K.

This information is furnished pursuant to Item 7.01 of Form 8-K and shall not be deemed to be “filed” for the purposes of Section 18 of the Securities Exchange Act of 1934 (“Exchange Act”), as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, of the Exchange Act, whether made before or after the date of this report, except as shall be expressly set forth by specific reference in such filing.

Item 9.01 Financial Statements and Exhibits.

d) Exhibits .

Exhibit

Number

Description

Location

99.1

Press Release issued by Financial Institutions, Inc. on April 23, 2026

Filed Herewith

104

Cover Page Interactive Data File (embedded within the Inline XBRL document)