Isabella Bank Corp Announces Election Mailings to Grand River Shareholders

What Happened Isabella Bank Corporation filed a Form 8-K on September 28, 2026, reporting that it issued a press release announcing the mailing of election materials to Grand River Commerce, Inc. shareholders and identifying an election deadline. The press release is attached to the 8-K as Exhibit 99.1 and is incorporated by reference.

Key Details

• Filing date: September 28, 2026 (Form 8-K, Item 8.01 — Other Events).
• Event: Mailing of election materials to shareholders of Grand River Commerce, Inc.; an election deadline was announced.
• Attached: Press release dated September 28, 2026 is included as Exhibit 99.1 to the Form 8-K.
• Report signed by Gerald J. Ritzert, Chief Financial Officer of Isabella Bank Corporation.

Why It Matters This filing notifies investors that Isabella Bank is actively communicating with Grand River Commerce shareholders about a shareholder election and has set a deadline for that vote. Holders of Grand River Commerce stock should expect and review the mailed materials and take any voting action before the stated deadline. For Isabella Bank investors, the update signals progress in whatever shareholder matter requires the election (e.g., governance or transactional approvals) and is a formal step in the process.