Isabella Bank (ISBA) S-3DPOS Registration of securities, dividend or interest reinvestment plans, immediately effective (post-effective amendment)

Exhibit 99.1

To be used by current Isabella Bank Corporation shareholders only. If you are not currently a shareholder, please contact Shareholder Services at (989) 779-6237, the financial advisors of Raymond James Financial Services located at Isabella Bank, or any other licensed broker.

Authorization Card
Stockholder Dividend	STOCK PURCHASE FORM -- I hereby appoint the Plan Administrator as my agent under
Reinvestment and Employee	the terms and conditions of the Plan, as described in the Prospectus for the Plan, to receive
Stock Purchase Plan Stock	and apply the following to the purchase of the shares, without charge, as provided in the Plan:
Purchase Form
---------	DIVIDEND REINVESTMENT (Please select only one option)
So that we may identify your	¨	1	FULL DIVIDEND REINVESTMENT- Any dividends that may become payable to me
account, please PRINT the			on all Isabella Bank Corporation Common Stock now or hereafter registered to me
following information in			subject to any maximum amount set by Isabella Bank Corporation from time to time.
addition to signing the card.	¨	2	PARTIAL DIVIDEND REINVESTMENT- Any dividends that may become payable to
			me on the following shares of my Isabella Bank Corporation Common Stock.
			SHARES _______________ subject to any maximum amount set by Isabella
			Bank Corporation from time to time.
Name:
______________________	OPTIONAL CASH INVESTMENT (Please select only one option; said option shall be
Address:	subject to any minimum or maximum amounts set by Isabella Bank Corporation from time to
______________________	time.)
______________________	¨	1	CHECK OR MONEY ORDER - The amount payable on the enclosed check or
Phone Number:			money order made payable to Isabella Bank Corporation.
______________________	¨	2	AUTOMATIC BANK WITHDRAWAL - $ _______________, which amount is not
Email (if applicable):			less than $25 and shall be automatically deducted from my United States bank
______________________			account identified below by either a:
			¨ ONE-TIME AUTOMATIC BANK WITHDRAWAL or
			¨ MONTHLY AUTOMATIC BANK WITHDRAWAL
			Name of Financial Institution _________________________
			Type of Account: ¨ Checking ¨ Savings
			Account Number: ____________________
			Routing Number: ____________________
	I understand that, if I selected Monthly Automatic Bank Withdrawals, my United States bank
	account identified above will be debited monthly in the amount requested on or about the
	15th day of each month, until I change or revoke this authorization card.
	I acknowledge that dividends received on shares held in my Plan account will automatically
	be reinvested in additional Common Stock.
	Date: ____________________
	Signature: ____________________________________________________________

•Please check only one of the boxes No. 1 or No. 2 under "DIVIDEND REINVESTMENT," and only one of the boxes No. 1 or No. 2 under "OPTIONAL CASH INVESTMENT." If you check box No. 2 under "OPTIONAL CASH INVESTMENT." you must also check a box to indicate whether the Automatic Bank Withdrawal should be one-time or monthly, and you must provide accurate account information.

•Please be sure to sign and date the form. Return completed forms to:

Isabella Bank Corporation, 401 N. Main St., Mt. Pleasant, MI 48858

Attention: Shareholder Services

You may request additional Authorization Cards at any time by writing to the above address or by calling Debbie Campbell at (989) 779-6237. We will also periodically mail you a new Authorization Card.