Exhibit 23

Consent of Independent Registered Public Accounting Firm

We hereby consent to the incorporation by reference in the registration statements (Form S-3 No. 333-249855 and Form S-8 No. 333-263014) pertaining to the Isabella Bank Corporation Stockholder Dividend Reinvestment and Employee Stock Purchase Plan of our integrated audit report dated March 15, 2022, relating to the consolidated financial statements and the effectiveness of internal control over financial reporting of Isabella Bank Corporation, included in this Annual Report on Form 10-K for the year ended December 31, 2021.

	/s/ Rehmann Robson LLC
Saginaw, Michigan
March 15, 2022