Exhibit 99.1

For Immediate Release

Isabella Bank Corporation

401 North Main Street

Mt. Pleasant, MI 48858-1649

FOR MORE INFORMATION CONTACT:

Trish Tomczak, Director of Marketing

Phone: 989-779-6333 Fax: 989-775-5501

Strong Fourth Quarter Caps Record Year for Isabella Bank Corporation

Record Net Income and EPS in 2022; EPS up 19% over 2021

Mt. Pleasant, Michigan, February 9, 2023 — Isabella Bank Corporation (the “Corporation”) (OTCQX: ISBA) reported record net income, net interest income and earnings per share for the year ended December 31, 2022. Fourth quarter net income was $6.3 million, surpassing $4.8 million for the same period in 2021, resulting in net income of $22.2 million in 2022, up 14% from $19.5 million reported in 2021. Earnings per common share were $0.84 in the fourth quarter and $2.95 for the year, above the $0.63 and $2.48 reported for the same periods a year ago, respectively.

"Isabella Bank had another outstanding year, driven by solid growth across our geographic and business portfolios and a favorable interest rate environment," said Jae A. Evans, President & CEO. "We are seeing the results of implementing our strategic plan, which led to increased market share in several markets, by investing in digital technology and new offerings."

Additional 2022 highlights:

•Total deposits increased $33.9 million in 2022, or 2%.

•Fourth quarter net interest income rose $2.8 million, or 21%, over the same period in 2021, and net interest income was $7.8 million in 2022, up 15% from 2021.

•Net yield on interest earning assets reached 3.43% in the fourth quarter, up from 2.86% for the same period in 2021.

•Asset quality also improved, with nonperforming loans at 0.04% of total loans, compared to 0.10% at the end of 2021.

“We are attracting new customers, while also expanding our offerings with current customers," Evans added. "This is possible because of our outstanding Isabella Bank team. We remain committed to growing with our customers and communities, just as we have since 1903. Our reputation as a strong, reliable and community-focused bank will not change, even as we continue to evolve to provide the services our customers and communities want and need."

Operating Results

Net income: Fourth quarter 2022 net income increased 31.9% compared to the same period in 2021. For the year ended December 31, 2022, net income was $22.2 million, compared to $19.5 million in 2021.

Net interest income, fourth quarter 2022: Net interest income for the fourth quarter 2022 improved by $2.8 million, or 21%, compared to the fourth quarter of 2021. Interest income increased $2.9 million, or 19.1%, driven largely by rising interest rates.

Net interest income: Net interest income for the year ended December 31, 2022 increased $7.8 million to $60.5 million, up 14.8% compared to 2021. While Paycheck Protection Program loan fees declined, rising interest rates and growth in available-for-sale securities led to a $5.7 million, or 9.5%, increase in gross interest income for the year ended December 31, 2022, compared to 2021. The Corporation continued to benefit from the significant reduction in its higher-cost borrowings — a strategic move that commenced in 2019 and contributed to a $2.1 million, or 28.3%, decrease in interest expense on deposits and borrowings for the year ended December 31, 2022, when compared to 2021. The provision for loan loss in 2022 was $483,000 compared to a $518,000 provision reversal in 2021, when concerns over potential credit quality issues related to the pandemic did not materialize.

Noninterest income and expenses, fourth quarter 2022: Noninterest income decreased $336,000 compared to the fourth quarter of 2021, primarily driven by a reduction in gain on sale of mortgage loans. Noninterest expenses for the quarter increased $725,000, attributed to increased compensation, equipment, and loan underwriting expenses.

Noninterest income and expenses: Noninterest income for the year ended December 31, 2022 decreased $156,000 compared to 2021. Gain on sale of mortgages decreased $1.1 million, as demand for residential mortgage originations declined due to the rising interest rate environment. This was offset by an increase in service charges and fees of $1.1 million, with $619,000 of the increase related to mortgage servicing rights. Noninterest expense increased $3.1 million in 2022 compared to 2021, primarily the result of increased compensation, other losses, and donations and community relations expenses.

Net yield on interest earning assets: The Corporation’s fully taxable equivalent net yield on interest earning assets was 3.43% and 3.18% for the fourth quarter and year ended 2022, respectively, compared to 2.86% and 2.87% for the same periods in 2021. The marked improvement is a result of strategies that positioned the Bank to benefit in a rising interest rate environment, including a reduced reliance on higher-cost borrowed funds and brokered deposits.

Balance Sheet

Assets: Total assets were $2.03 billion and assets under management were $2.81 billion as of December 31, 2022. Managed assets included loans sold and serviced of $264.2 million as well as $513.9 million in investment and trust assets managed by Isabella Wealth.

Loans: Loans outstanding as of December 31, 2022 totaled $1.26 billion. Core loan growth improved $35.1 million, or 2.9%, primarily due to commercial loan growth. Gross loans declined $36.9 million since December 31, 2021 due to a decrease of $72 million in advances to mortgage brokers, which are included in the commercial loan portfolio but are not considered a component of the Bank's core lending business. While the Bank has experienced fluctuations in credit quality indicators in recent periods, credit quality remained strong, as evidenced by total past due and nonaccrual loans being just 0.88% of gross loans as of December 31, 2022. Additionally, nonperforming loans at year end 2022 declined to $457,000, or 0.04% of total loans, compared to $1.3 million, or 0.10%, at December 31, 2021.

Deposits: Growth in accounts from new customers drove total deposits to $1.74 billion as of December 31, 2022, an increase of $33.9 million, or 2.0%, since December 31, 2021. A large percentage of this increase came in the form of demand deposits which helps to minimize total interest expense and reduce overall cost of funds.

Capital: Due to an increase in short-term and intermediate-term benchmark interest rates, unrealized losses related to available-for-sale securities increased significantly during 2022. As a result, shareholders' equity has declined, negatively impacting tangible book value. The Bank continues to be considered a “well-capitalized” institution, as its capital ratios exceeded the minimum designated requirements. As of December 31, 2022, the Bank’s Tier 1 Leverage Ratio was 9.36%, Tier 1 Capital Ratio was 14.07% and Total Capital Ratio was 14.80%. The minimum requirements to be considered well capitalized are a Tier 1 Leverage Ratio of 5.0%, Tier 1 Capital Ratio of 8.0% and Total Capital Ratio of 10.0%.

Dividend: The Corporation paid a $0.28 per common share cash dividend for the fourth quarter of 2022, an increase of 3.7% compared to fourth quarter of 2021. Total cash dividends paid for the year ended December 31, 2022 totaled $1.09. Based on the Corporation’s closing stock price of $23.50 as of December 31, 2022, the annualized cash dividend yield was 4.77%.

About the Corporation

Isabella Bank Corporation (OTCQX: ISBA) is the parent holding company of Isabella Bank, a state chartered community bank headquartered in Mt. Pleasant, Michigan. Isabella Bank was established in 1903 and has been committed to serving the local banking needs of its customers and communities for 120 years. The Bank offers personal and commercial lending and deposit products, as well as investment, trust, and estate planning services through Isabella Wealth. The Bank has locations throughout seven Mid-Michigan counties: Clare, Gratiot, Isabella, Mecosta, Midland, Montcalm, and Saginaw.

For more information about Isabella Bank Corporation, visit the investors link at www.isabellabank.com. Isabella Bank Corporation common stock is quoted on the OTCQX tier of the OTC Markets Group, Inc.’s electronic quotation system (www.otcmarkets.com) under the symbol “ISBA.” The Corporation’s investor relations firm is Renmark Financial Communications, Inc. (www.renmarkfinancial.com).

Forward-Looking Statements

This press release includes forward-looking statements. To the extent that the foregoing information refers to matters that may occur in the future, please be aware that such forward-looking statements may differ materially from the actual results. Additional information concerning some of the factors that could cause materially different results is included in the sections titled “Risk Factors” and “Forward Looking Statements” set forth in Isabella Bank Corporation’s filings with the Securities and Exchange Commission, which are available from the Securities and Exchange Commission’s Public Reference facilities and from its website at www.sec.gov.

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED)

(Dollars in thousands)

			December 31 2022						December 31 2021
ASSETS
Cash and cash equivalents
Cash and demand deposits due from banks			$	27,420					$	25,563
Fed Funds sold and interest bearing balances due from banks			11,504						79,767
Total cash and cash equivalents			38,924						105,330
Available-for-sale securities, at fair value			580,481						490,601
Mortgage loans available-for-sale			379						1,735
Loans
Commercial			740,920						807,439
Agricultural			104,314						93,955
Residential real estate			340,885						326,361
Consumer			78,054						73,282
Gross loans			1,264,173						1,301,037
Less allowance for loan and lease losses			9,850						9,103
Net loans			1,254,323						1,291,934
Premises and equipment			25,553						24,419
Corporate owned life insurance policies			32,988						32,472
Equity securities without readily determinable fair values			15,746						17,383
Goodwill and other intangible assets			48,287						48,302
Accrued interest receivable and other assets			33,586						19,982
TOTAL ASSETS			$	2,030,267					$	2,032,158
LIABILITIES AND SHAREHOLDERS’ EQUITY
Deposits
Noninterest bearing			$	494,346					$	448,352
Interest bearing demand deposits			372,155						364,563
Certificates of deposit under $250 and other savings			810,642						818,841
Certificates of deposit over $250			67,132						78,583
Total deposits			1,744,275						1,710,339
Borrowed funds
Federal funds purchased and repurchase agreements			57,771						50,162
Federal Home Loan Bank advances			—						20,000
Subordinated debt, net of unamortized issuance costs			29,245						29,158
Total borrowed funds			87,016						99,320
Accrued interest payable and other liabilities			12,766						11,451
Total liabilities			1,844,057						1,821,110
Shareholders’ equity
Common stock — no par value 15,000,000 shares authorized; issued and outstanding 7,559,421 shares (including 154,879 shares held in the Rabbi Trust) in 2022 and 7,532,641 shares (including 105,654 shares held in the Rabbi Trust) in 2021			128,651						129,052
Shares to be issued for deferred compensation obligations			5,005						4,545
Retained earnings			89,748						75,592
Accumulated other comprehensive income (loss)			(37,194)						1,859
Total shareholders’ equity			186,210						211,048
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY			$	2,030,267					$	2,032,158

CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED)

(Dollars in thousands except per share amounts)

			Three Months Ended   December 31												Year Ended  December 31
			2022						2021						2022						2021
Interest income
Loans, including fees			$	14,163					$	12,776					$	53,283					$	51,410
Available-for-sale securities
Taxable			2,512						1,391						8,363						4,920
Nontaxable			718						684						2,808						3,077
Federal funds sold and other			522						190						1,344						706
Total interest income			17,915						15,041						65,798						60,113
Interest expense
Deposits			1,323						1,079						4,021						5,442
Borrowings
Federal funds purchased and repurchase agreements			53						13						79						53
Federal Home Loan Bank advances			—						209						152						1,302
Subordinated debt, net of unamortized issuance costs			267						266						1,065						615
Total interest expense			1,643						1,567						5,317						7,412
Net interest income			16,272						13,474						60,481						52,701
Provision for loan losses			(57)						81						483						(518)
Net interest income after provision for loan losses			16,329						13,393						59,998						53,219
Noninterest income
Service charges and fees			2,115						2,125						8,730						7,614
Wealth management fees			788						797						3,005						3,071
Earnings on corporate owned life insurance policies			229						223						884						800
Net gain on sale of mortgage loans			63						235						631						1,694
Gains from redemption of corporate owned life insurance policies			—						121						57						271
Other			77						107						359						372
Total noninterest income			3,272						3,608						13,666						13,822
Noninterest expenses
Compensation and benefits			6,407						6,056						24,887						23,749
Furniture and equipment			1,624						1,413						6,006						5,462
Occupancy			878						935						3,691						3,661
Other			3,013						2,793						12,236						10,822
Total noninterest expenses			11,922						11,197						46,820						43,694
Income before federal income tax expense			7,679						5,804						26,844						23,347
Federal income tax expense			1,357						1,010						4,606						3,848
NET INCOME			$	6,322					$	4,794					$	22,238					$	19,499
Earnings per common share
Basic			$	0.84					$	0.63					$	2.95					$	2.48
Diluted			$	0.83					$	0.63					$	2.91					$	2.45
Cash dividends per common share			$	0.28					$	0.27					$	1.09					$	1.08

AVERAGE BALANCES, INTEREST RATE, AND NET INTEREST INCOME (UNAUDITED)

(Dollars in thousands)

The following schedules present the daily average amount outstanding for each major category of interest earning assets, non-earning assets, interest bearing liabilities, and noninterest bearing liabilities. These schedules also present an analysis of interest income and interest expense for the periods indicated. All interest income is reported on a fully taxable equivalent (FTE) basis using a federal income tax rate of 21%. Loans in nonaccrual status, for the purpose of the following computations, are included in the average loan balances. Federal Reserve Bank (FRB) and Federal Home Loan Bank (FHLB) restricted equity holdings are included in other interest earning assets.

			Three Months Ended
			December 31, 2022																		December 31, 2021
			Average Balance						Tax Equivalent Interest						Average Yield / Rate						Average Balance						Tax Equivalent Interest						Average Yield / Rate
INTEREST EARNING ASSETS
Loans			$	1,244,972					$	14,163					4.55		%				$	1,226,192					$	12,776					4.17		%
Taxable investment securities			520,139						2,499						1.92		%				383,175						1,391						1.45		%
Nontaxable investment securities			107,508						999						3.72		%				104,115						889						3.42		%
Fed funds sold			14						—						4.00		%				9						—						0.01		%
Other			56,142						522						3.72		%				199,605						190						0.38		%
Total earning assets			1,928,775						18,183						3.77		%				1,913,096						15,246						3.19		%
NONEARNING ASSETS
Allowance for loan losses			(9,792)																		(9,082)
Cash and demand deposits due from banks			24,312																		28,852
Premises and equipment			25,382																		24,534
Accrued income and other assets			63,553																		109,238
Total assets			$	2,032,230																	$	2,066,638
INTEREST BEARING LIABILITIES
Interest bearing demand deposits			$	358,809					$	104					0.12		%				$	367,130					$	48					0.05		%
Savings deposits			635,771						535						0.34		%				584,475						157						0.11		%
Time deposits			254,604						684						1.07		%				306,817						874						1.14		%
Federal funds purchased and repurchase agreements			55,478						53						0.38		%				60,508						13						0.09		%
Federal Home Loan Bank advances			—						—						—		%				40,543						209						2.06		%
Subordinated debt, net of unamortized issuance costs			29,233						267						3.65		%				29,143						266						3.65		%
Total interest bearing liabilities			1,333,895						1,643						0.49		%				1,388,616						1,567						0.45		%
NONINTEREST BEARING LIABILITIES
Demand deposits			504,791																		449,766
Other			13,103																		12,002
Shareholders’ equity			180,441																		216,254
Total liabilities and shareholders’ equity			$	2,032,230																	$	2,066,638
Net interest income (FTE)									$	16,540																	$	13,679
Net yield on interest earning assets (FTE)															3.43		%																2.86		%

			Year Ended
			December 31, 2022																		December 31, 2021
			Average Balance						Tax Equivalent Interest						Average Yield / Rate						Average Balance						Tax Equivalent Interest						Average Yield / Rate
INTEREST EARNING ASSETS
Loans			$	1,249,634					$	53,283					4.26		%				$	1,208,141					$	51,410					4.26		%
Taxable investment securities			477,159						8,294						1.74		%				297,357						4,920						1.65		%
Nontaxable investment securities			107,158						3,933						3.67		%				117,997						4,235						3.59		%
Fed funds sold			10						—						2.42		%				5						—						0.02		%
Other			99,301						1,344						1.35		%				255,246						706						0.28		%
Total earning assets			1,933,262						66,854						3.46		%				1,878,746						61,271						3.26		%
NONEARNING ASSETS
Allowance for loan losses			(9,477)																		(9,396)
Cash and demand deposits due from banks			24,708																		29,139
Premises and equipment			24,648																		24,760
Accrued income and other assets			81,823																		109,625
Total assets			$	2,054,964																	$	2,032,874
INTEREST BEARING LIABILITIES
Interest bearing demand deposits			$	374,623					$	274					0.07		%				$	345,015					$	216					0.06		%
Savings deposits			630,574						1,135						0.18		%				558,102						616						0.11		%
Time deposits			270,296						2,612						0.97		%				336,094						4,610						1.37		%
Federal funds purchased and repurchase agreements			49,974						79						0.16		%				57,453						53						0.09		%
Federal Home Loan Bank advances			7,863						152						1.93		%				69,342						1,302						1.88		%
Subordinated debt, net of unamortized issuance costs			29,200						1,065						3.65		%				17,000						615						3.62		%
Total interest bearing liabilities			1,362,530						5,317						0.39		%				1,383,006						7,412						0.54		%
NONINTEREST BEARING LIABILITIES
Demand deposits			482,781																		416,247
Other			14,695																		12,858
Shareholders’ equity			194,958																		220,763
Total liabilities and shareholders’ equity			$	2,054,964																	$	2,032,874
Net interest income (FTE)									$	61,537																	$	53,859
Net yield on interest earning assets (FTE)															3.18		%																2.87		%

SELECTED FINANCIAL DATA (UNAUDITED)

(Dollars in thousands except per share amounts)

			Year Ended
			December 31 2022						December 31 2021						December 31 2020
PER SHARE
Basic earnings			$	2.95					$	2.48					$	1.37
Diluted earnings			$	2.91					$	2.45					$	1.34
Dividends			$	1.09					$	1.08					$	1.08
Tangible book value			$	18.25					$	21.61					$	21.29
Quoted market value
High			$	26.25					$	29.00					$	24.50
Low			$	21.00					$	19.45					$	15.60
Close (1)			$	23.50					$	25.50					$	19.57
Common shares outstanding (1)			7,559,421						7,532,641						7,997,247
Average number of common shares outstanding			7,549,878						7,853,398						7,959,705
Average number of diluted common shares outstanding			7,647,612						7,965,961						8,106,091
PERFORMANCE RATIOS
Return on average total assets			1.08		%				0.96		%				0.57		%
Return on average shareholders' equity			11.41		%				8.83		%				4.93		%
Return on average tangible shareholders' equity			15.17		%				11.31		%				6.34		%
Net interest margin yield (FTE)			3.18		%				2.87		%				2.96		%
ASSETS UNDER MANAGEMENT (1)
Loans sold with servicing retained			$	264,206					$	278,844					$	301,377
Assets managed by Isabella Wealth			$	513,918					$	516,243					$	443,967
Total assets under management			$	2,808,391					$	2,827,245					$	2,702,722
ASSET QUALITY (1)
Nonaccrual status loans			$	457					$	1,245					$	5,313
Performing troubled debt restructurings			$	21,069					$	25,276					$	22,200
Foreclosed assets			$	439					$	211					$	527
Net loan charge-offs (recoveries)			$	(264)					$	123					$	(140)
Nonperforming loans to gross loans			0.04		%				0.10		%				0.43		%
Nonperforming assets to total assets			0.05		%				0.08		%				0.31		%
Allowance for loan and lease losses to gross loans			0.78		%				0.70		%				0.79		%
CAPITAL RATIOS (1)
Shareholders' equity to assets			9.17		%				10.39		%				11.17		%
Tier 1 leverage			8.61		%				7.97		%				8.37		%
Common equity tier 1 capital			12.91		%				12.07		%				12.97		%
Tier 1 risk-based capital			12.91		%				12.07		%				12.97		%
Total risk-based capital			15.79		%				14.94		%				13.75		%

(1) At end of period

SUPPLEMENTAL BALANCE SHEET DATA (UNAUDITED)

(Dollars in thousands)

			December 31 2022						September 30 2022						June 30 2022						March 31 2022						December 31 2021
Commercial			$	740,920					$	730,504					$	772,567					$	727,614					$	807,439
Agricultural			104,314						96,850						94,726						88,169						93,955
Residential real estate			340,885						334,412						329,795						328,559						326,361
Consumer			78,054						74,385						74,822						74,029						73,282
Gross loans			$	1,264,173					$	1,236,151					$	1,271,910					$	1,218,371					$	1,301,037

			December 31 2022						September 30 2022						June 30 2022						March 31 2022						December 31 2021
Noninterest bearing demand deposits			$	494,346					$	510,127					$	488,110					$	461,473					$	448,352
Interest bearing demand deposits			372,155						368,537						370,284						387,187						364,563
Savings deposits			625,734						651,129						635,397						635,195						596,662
Certificates of deposit			251,541						260,741						265,477						279,708						297,696
Internet certificates of deposit			499						499						598						598						3,066
Total deposits			$	1,744,275					$	1,791,033					$	1,759,866					$	1,764,161					$	1,710,339

			December 31 2022						September 30 2022						June 30 2022						March 31 2022						December 31 2021
U.S. Treasury			$	208,701					$	206,791					$	214,474					$	218,268					$	209,703
States and political subdivisions			117,512						114,000						119,649						114,015						121,205
Auction rate money market preferred			2,342						2,479						2,497						2,867						3,242
Mortgage-backed securities			39,070						41,042						45,796						49,578						56,148
Collateralized mortgage obligations			205,728						209,720						167,572						152,441						92,301
Corporate			7,128						7,201						7,602						7,750						8,002
Available-for-sale securities, at fair value			$	580,481					$	581,233					$	557,590					$	544,919					$	490,601

			December 31 2022						September 30 2022						June 30 2022						March 31 2022						December 31 2021
Securities sold under agreements to repurchase without stated maturity dates			$	57,771					$	52,479					$	47,247					$	51,353					$	50,162
Federal Home Loan Bank advances			—						—						10,000						10,000						20,000
Subordinated debt, net of unamortized issuance costs			29,245						29,225						29,203						29,181						29,158
Total borrowed funds			$	87,016					$	81,704					$	86,450					$	90,534					$	99,320

SUPPLEMENTAL STATEMENTS OF INCOME DATA (UNAUDITED)

(Dollars in thousands)

			Three Months Ended   December 31												Year Ended  December 31
			2022						2021						2022						2021
Service charges and fees
ATM and debit card fees			$	1,267					$	1,318					$	4,774					$	4,600
Service charges and fees on deposit accounts			653						621						2,566						2,139
Freddie Mac servicing fee			163						175						669						747
Net mortgage servicing rights income (loss)			(42)						(56)						435						(184)
Other fees for customer services			74						67						286						312
Total service charges and fees			2,115						2,125						8,730						7,614
Wealth management fees			788						797						3,005						3,071
Earnings on corporate owned life insurance policies			229						223						884						800
Net gain on sale of mortgage loans			63						235						631						1,694
Gains from redemption of corporate owned life insurance policies			—						121						57						271
Other			77						107						359						372
Total noninterest income			$	3,272					$	3,608					$	13,666					$	13,822

			Three Months Ended   December 31												Year Ended  December 31
			2022						2021						2022						2021
Compensation and benefits			$	6,407					$	6,056					$	24,887					$	23,749
Furniture and equipment			1,624						1,413						6,006						5,462
Occupancy			878						935						3,691						3,661
Other
Audit, consulting, and legal fees			609						513						2,358						2,066
ATM and debit card fees			424						458						1,909						1,810
Marketing costs			244						256						1,056						939
Loan underwriting fees			364						221						1,004						849
Donations and community relations			258						253						923						705
Memberships and subscriptions			222						215						876						877
Director fees			192						198						790						703
FDIC insurance premiums			143						161						537						690
All other			557						518						2,783						2,183
Total other noninterest expenses			3,013						2,793						12,236						10,822
Total noninterest expenses			$	11,922					$	11,197					$	46,820					$	43,694