X0606 TA-2 2025-12-31 085-05559 0001526156 XXXXXXXX LIVE true false Isabella Bank Corp None N Board of Governors of the Federal Reserve System Not applicable 1841 2459 2459 1955 0 100.00 0.00 0.00 0.00 0.00 0.00 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 8238625.69 0 0.00 0 0.00 0 Yes 0 0 02/28/2025 1 0 04/14/2025 1 0 05/19/2025 1 0 07/14/2025 1 0 10/09/2025 1 0 10/14/2025 1 0 10/30/2025 1 0 0 /s/ Debra A. Campbell (989) 779-6237 Vice President/Corporate Secretary 03/19/2026