Bylaw Amendment · Shareholder Vote

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 ____________________ FORM 8-K _________________________________________ Current report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 21, 2026 _______________________ (Exact name of registrant as specified in its charter) _______________________ California 0-10661 94-2792841 (State or other jurisdiction of incorporation or organization) (Commission File No.) (I.R.S. Employer Identification No.) 63 Constitution Drive Chico, California 95973 (Address of principal executive offices) (Zip Code) Registrant’s telephone number, including area code: ( 530 )  898-0300 _____________________ Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each class Trading Symbol(s) Name of each exchange on which registered Common Stock, no par value TCBK Nasdaq Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐ Item 5.03 Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year On May 21, 2026, TriCo Bancshares (the “Company”) held its 2026 annual meeting of shareholders (the “Annual Meeting”). At the Annual Meeting, the Company’s shareholders voted on a proposal to amend the Company’s bylaws to eliminate cumulative voting (the “Amendment”). The Company’s shareholders adopted and approved the Amendment, as further described in Item 5.07 to this Current Report on Form 8-K. Following the shareholders’ approval of the Amendment, on May 21, 2026, the Board implemented the Amendment by adopting and approving amended and restated bylaws of the Company (the “Amended Bylaws”). Section 11 of the Amended Bylaws provides that shareholders may not cumulative votes in the election of directors. In addition, the Amended Bylaws, as adopted and approved by the Board, provide that the Board may appoint one or more Lead Directors with the authority to call and preside over Board meetings and such other duties as the Board may determine. The Amended Bylaws also amend the previously existing indemnity provisions in Section 50 to clarify that the both current and former agents of the Company may be entitled to indemnity by the Company. The foregoing summary of the Amended Bylaws does not purport to be complete and is qualified in its entirety by the Amended Bylaws, copies of which are attached as Exhibit 3.2 to this Current Report on Form 8-K and are incorporated herein by referenc e. Item 5.07 Submission of Matters to a Vote of Security Holders On May 21, 2026, the Company held its Annual Meeting. As of the record date for the Annual Meeting, there were 31,910,590 shares of common stock outstanding entitled to vote on all proposals presented at the Annual Meeting. 28,103,170 shares of common stock, or 88.07% of the total outstanding, were present at the meeting in person or by proxy. At the Annual Meeting, the Company’s shareholders voted on the following four proposals and cast their votes as described below. 1. The individuals listed below were elected at the Annual Meeting to serve as directors of the Company until the next annual meeting of shareholders and until their successors are duly elected and qualified: Nominee For Withheld Abstained/Broker Non-Votes Kirsten E. Garen 25,042,555 149,731 2,910,883 Cory W. Giese 24,905,039 287,247 2,910,883 John S. A. Hasbrook 24,510,023 682,263 2,910,883 Margaret L. Kane 24,968,273 224,014 2,910,883 Michael W. Koehnen 24,961,601 230,685 2,910,883 Anthony L. Leggio 25,025,952 166,335 2,910,883 Martin A. Mariani 24,852,270 340,016 2,910,883 Thomas C. McGraw 25,031,364 160,923 2,910,883 Jon Y. Nakamura 25,034,313 157,974 2,910,883 Richard P. Smith 24,892,678 299,609 2,910,883 Kimberley H. Vogel 25,036,409 155,877 2,910,883 2. A nonbinding advisory resolution to approve executive compensation was approved. Votes For 24,274,276  Against 638,564  Abstain 278,999  Broker Non-Votes 2,910,883  Uncast 447  3. A management proposal to amend TriCo Bancshares Bylaws to eliminate cumulative voting was approved. Votes For 16,321,837  Against 8,706,979  Abstain 163,023  Broker Non-Votes 2,910,883  Uncast 447  4.     A management proposal to ratify the appointment of Baker Tilly US, LLP as the Company’s independent public accountants for the 2026 fiscal year was approved. Votes For 27,885,107  Against 105,548  Abstain 112,067  Broker Non-Votes —  Uncast 447  Item 9.01 Financial Statements and Exhibits Exhibit No. Description 3.2 Bylaws of TriCo Bancshares, as amended and restated SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized. TRICO BANCSHARES Date: May 27, 2026 /s/ Peter G. Wiese Peter G. Wiese, Executive Vice President and Chief Financial Officer (Principal Financial and Accounting Officer)