UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 11-K

☑ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2022

OR

☐ TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from__________________________to__________________________

Commission file number      000-26719                 

Mercantile Bank of Michigan 401(k) Plan

Mercantile Bank Corporation

(Name of issuer of the securities held pursuant to the plan)

310 Leonard Street NW, Grand Rapids, Michigan, 49504

(full address of the executive office)

REQUIRED INFORMATION

THE MERCANTILE BANK OF MICHIGAN 401(K) PLAN IS SUBJECT TO THE EMPLOYEE RETIREMENT INCOME SECURITY ACT OF 1974 (ERISA). IN LIEU OF THE REQUIREMENTS OF ITEMS 1, 2 AND 3 OF FORM 11-K FOR ANNUAL REPORTS, THE FINANCIAL STATEMENTS AND SCHEDULES OF THE PLAN FOR THE TWO YEARS ENDED DECEMBER 31, 2022 AND 2021, WHICH HAVE BEEN PREPARED IN ACCORDANCE WITH THE FINANCIAL REPORTING REQUIREMENTS OF ERISA, ARE INCLUDED IN THIS REPORT.

Mercantile Bank of Michigan
401(k) Plan

Financial Statements and
Supplemental Schedule

Years Ended December 31, 2022 and 2021

The report accompanying these financial statements was issued by

BDO USA, LLP, a Delaware limited liability partnership and the U.S. member of BDO International Limited, a UK company limited by guarantee.

Mercantile Bank of Michigan 401(k) Plan

Financial Statements and Supplemental Schedule

Years Ended December 31, 2022 and 2021

Mercantile Bank of Michigan 401(k) Plan

Contents

Report of Independent Registered Public Accounting Firm	3-4
Financial Statements
Statements of Net Assets Available for Benefits as of December 31, 2022 and 2021	5
Statements of Changes in Net Assets Available for Benefits for the Years Ended December 31, 2022 and 2021	6
Notes to Financial Statements	7-11
ERISA-Required Supplemental Schedule	12
Schedule H, Line 4i – Schedule of Assets (Held at End of Year) as of December 31, 2022	13
Exhibit List	14
Signatures	15
Consent of Independent Registered Public Accounting Firm

2

Report of Independent Registered Public Accounting Firm

The Plan Administrator and Participants

Mercantile Bank of Michigan 401(k) Plan

Grand Rapids, Michigan

Opinion on the Financial Statements

We have audited the accompanying statements of net assets available for benefits of the Mercantile Bank of Michigan 401(k) Plan (the “Plan”) as of December 31, 2022 and 2021, the related statement of changes in net assets available for benefits for the year ended December 31, 2022, and the related notes (collectively, the “financial statements”). In our opinion, the financial statements present fairly, in all material respects, the net assets available for benefits of the Plan as of December 31, 2022 and 2021, and the changes in net assets available for benefits for the year ended December 31, 2022, in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

These financial statements are the responsibility of the Plan’s management. Our responsibility is to express an opinion on the Plan’s financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (“PCAOB”) and are required to be independent with respect to the Plan in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Plan is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits, we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Plan’s internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risk of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by the Plan’s management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

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Supplemental Information

The supplemental information in the accompanying Schedule of Assets (Held at End of Year) as of December 31, 2022 has been subjected to audit procedures performed in conjunction with the audit of the Plan’s financial statements. The supplemental information is presented for the purpose of additional analysis and is not a required part of the financial statements but included supplemental information required by the Department of Labor’s Rules and Regulations for Reporting and Disclosure under the Employee Retirement Income Security Act of 1974. The supplemental information is the responsibility of the Plan’s management. Our audit procedures included determining whether the supplemental information reconciles to the financial statements or the underlying accounting and other records, as applicable, and performing procedures to test the completeness and accuracy of the information presented in the supplemental information. In forming our opinion on the supplemental information, we evaluated whether the supplemental information, including its form and content, is presented in conformity with the Department of Labor’s Rules and Regulations for Reporting and Disclosure under the Employee Retirement Income Security Act of 1974. In our opinion, the supplemental information is fairly stated, in all material respects, in relation to the financial statements as a whole.

(Signed BDO USA, LLP)

We have served as the Plan’s auditor since 2006.

Grand Rapids, Michigan

June 23, 2023

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Mercantile Bank of Michigan 401(k) Plan

Statements of Net Assets Available for Benefits

December 31,	2022		2021
Assets
Investments, at fair value
Mutual funds	$	62,062,422	$	73,459,706
Mercantile Bank Corporation common stock		15,782,639		16,213,951
Money market fund		2,433,662		3,428,701
Total Investments		80,278,723		93,102,358
Notes Receivable from Participants		719,883		795,476
Accrued Investment Income		23,941		23,424
Net Assets Available for Benefits	$	81,022,547	$	93,921,258

See accompanying notes to financial statements.

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Mercantile Bank of Michigan 401(k) Plan

Statements of Changes Net Assets Available for Benefits

Year ended December 31,	2022			2021
Additions
Investment (loss) income:
Net (depreciation) appreciation in fair value of investments	$	(16,422,916	)	$	10,784,480
Interest and dividends		3,530,206			3,834,468
Total Investment (Loss) Income		(12,892,710	)		14,618,948
Contributions:
Employer		2,246,889			2,089,405
Employee		3,875,276			3,591,693
Rollover		542,320			1,033,787
Total Contributions		6,664,485			6,714,885
Interest from notes receivable		36,556			38,035
Total (Deductions) Additions		(6,191,669	)		21,371,868
Deductions
Benefits paid to participants		6,483,229			6,750,939
Administrative expenses		223,813			229,512
Total Deductions		6,707,042			6,980,451
Net (Decrease) Increase		(12,898,711	)		14,391,417
Net Assets Available for Benefits, beginning of year		93,921,258			79,529,841
Net Assets Available for Benefits, end of year	$	81,022,547		$	93,921,258

See accompanying notes to financial statements.

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Mercantile Bank of Michigan 401(k) Plan

Notes to Financial Statements

1. Plan Description

The following description of Mercantile Bank of Michigan 401(k) Plan (Plan) provides only general information. Participants should refer to the Plan Agreement for a more complete description of the Plan’s provisions.

General

The Plan was established by the Plan Sponsor, Mercantile Bank (Bank), effective January 1, 1998. The Plan was amended and restated effective January 1, 2019. The Plan is subject to the Employee Retirement Income Security Act of 1974 (ERISA).

Eligibility and Enrollment

The Plan is a defined contribution plan covering eligible employees who have completed a minimum of one hour of service. Eligible employees can enter the Plan on the first day of the month following date of hire. For newly eligible employees, the Plan provides automatic enrollment for the employee at an amount equal to 5% of compensation, until such time as the employee elects a different percentage or elects no contributions.

Contributions

Elective deferrals by participants under the Plan provisions are based on a percentage of their compensation, subject to certain limitations as defined by the Plan Agreement. Participants may also make after tax Roth contributions and may roll over account balances from other qualified defined benefit or defined contribution plans into their account.

The Bank makes safe harbor matching contributions equal to 100% of the first 5% of compensation deferred by each participant subject to certain limitations as specified in the Plan Document. The Bank may also make a discretionary profit-sharing contribution subject to certain limitations as specified in the Plan Agreement. There were no profit-sharing contributions in 2022 or 2021.

Participant Accounts

Each participant’s account is credited with the participant’s contributions, allocations of the Bank’s matching contribution, and Plan earnings. Allocations are based on participant earnings or account balances, as defined. The benefit to which a participant is entitled is the benefit that can be provided from the participant’s account. Participants may direct the investment of their account balances into various investment options offered by the Plan.

Vesting

Participants are immediately vested in their elective deferrals and all employer contributions and earnings thereon.

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Mercantile Bank of Michigan 401(k) Plan

Notes to Financial Statements

Notes Receivable from Participants

Participants may borrow from their accounts a minimum of $1,000 up to a maximum equal to the lesser of $50,000 or 50% of their account balance. The notes are secured by the balance in the participant’s account and bear interest at rates that are commensurate with local borrowing rates. Interest rates on notes receivable outstanding as of December 31, 2022 ranged from 4.25% to 9.25% Principal and interest is paid ratably through payroll deductions over a period not to exceed five years, unless the notes were used to purchase a primary residence, in which case the note terms shall not exceed ten years.

Payment of Benefits

Upon separation of service, death, disability or retirement, a participant or his or her beneficiary will receive a distribution of the participant’s account as a lump-sum amount or an installment option. A participant may receive the portion of his or her account invested in Mercantile Bank Corporation common stock in either common shares or cash. Additionally, under certain circumstances of financial hardship, participants are allowed to withdraw funds from the Plan.

Administrative Expenses

Certain administrative expenses are paid by the Plan Sponsor. Certain fees incurred as a result of participant-directed transactions (e.g., participant loan origination and distribution fees) are passed on to the participant. A trustee fee is paid to the Plan’s trustee and recordkeeper, Greenleaf Trust, which is calculated quarterly based on the market value of the Plan assets and allocated to participant accounts on a quarterly basis.

2. Significant Accounting Policies

Basis of Accounting

The accompanying financial statements are prepared under the accrual method of accounting.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of net assets and changes therein. Actual results could differ from those estimates.

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Mercantile Bank of Michigan 401(k) Plan

Notes to Financial Statements

Risks and Uncertainties

The Plan invests in various investment securities. Investment securities are exposed to various risks such as interest rate, market and credit risks. Due to the level of risk associated with certain investment securities, it is at least reasonably possible that changes in the values of investment securities will occur in the near term and that such changes could materially affect participants’ account balances and the amounts reported in the financial statements.

Concentration of Credit Risk

At December 31, 2022 and 2021, approximately 19% and 17%, respectively, of the Plan’s assets were invested in Mercantile Bank Corporation common stock. A significant decline in the market value of the common stock would significantly affect the net assets available for benefits.

Investment Valuation and Income Recognition

The Plan’s investments are stated at estimated fair value. Fair value is the price that would be received to sell an asset (an exit price) in the principal or most advantageous market for the asset in an orderly transaction between market participants on the measurement date. See Note 3 for discussion of fair value measurements.

Purchases and sales of securities are recorded on a trade date basis. Interest income is recorded on the accrual basis. Dividends are recorded on the ex-dividend date. Net appreciation (depreciation) includes the Plan’s gains and losses on investments bought and sold as well as held during the year.

Notes Receivable – Participant Loans

Participant loans are classified as notes receivable from participants, and are measured at the unpaid principal balance plus unpaid accrued interest. Defaulted loans, if any, are reclassified as distributions based upon the terms of the Plan Document.

Payment of Benefits

Benefits are recorded when paid.

Subsequent Events

Subsequent events have been evaluated by management through June 23, 2023 the date these financial statements were available to be issued.

3. Investments

In accordance with ASC 820, Fair Value Measurements and Disclosures, the Plan utilizes a fair value hierarchy for valuation inputs that gives the highest priority to quoted prices in active markets for identical assets (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The three levels of the fair value hierarchy are described as follows:

Level 1 - Inputs to the valuation methodology are unadjusted quoted prices for identical assets in active markets.

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Mercantile Bank of Michigan 401(k) Plan

Notes to Financial Statements

Level 2 - Inputs to the valuation methodology include quoted prices for similar assets in active markets, quoted prices for identical or similar assets in inactive markets, and other inputs that are observable or can be corroborated by observable market data.

Level 3 - Inputs to the valuation methodology are both significant to the fair value measurement and unobservable.

The following valuation methodologies were used to measure the fair value of the Plan’s investments. There were no changes in the methodologies used at December 31, 2022 or 2021.

Money Market and Mutual Funds - Valued at quoted market prices in an exchange and active market, which represent the net asset value of shares held by the Plan.

Mercantile Bank Corporation Common Stock - Valued at the closing price reported on the active market on which the security is traded.

The Plan’s valuation methods may result in a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. Although Plan management believes the valuation methods are appropriate and consistent with the market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different fair value measurement at the reporting date.

The tables below set forth by level within the fair value hierarchy the Plan’s investments.

December 31, 2022
	Level 1		Level 2		Level 3		Total
Mutual funds	$	62,062,422	$	-	$	-	$	62,062,422
Common stock		15,782,639		-		-		15,782,639
Money market fund		2,433,662		-		-		2,433,662
Investments, at fair value	$	80,278,723	$	-	$	-	$	80,278,723

December 31, 2021
	Level 1		Level 2		Level 3		Total
Mutual funds	$	73,459,706	$	-	$	-	$	73,459,706
Common stock		16,213,951		-		-		16,213,951
Money market fund		3,428,701		-		-		3,428,701
Investments, at fair value	$	93,102,358	$	-	$	-	$	93,102,358

4. Related Party Transactions

Parties-in-interest are defined under Department of Labor regulations as any fiduciary of the Plan, any party rendering service to the Plan, the employer and certain other parties. Professional fees for the administration and audit of the Plan are paid by the Bank. Notes receivable from participants are also considered party-in interest transactions.

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Mercantile Bank of Michigan 401(k) Plan

Notes to Financial Statements

The 471,405 and 462,859 shares of Mercantile Bank Corporation common stock held by the Plan as of December 31, 2022 and 2021, respectively, represent 2.95% and 2.92% of the Corporation’s outstanding shares as of December 31, 2022 and 2021, respectively.

Cash dividends of $581,960 and $537,692 were paid to the Plan by Mercantile Bank Corporation during 2022 and 2021, respectively.

5. Plan Termination

Although it has not expressed any intent to do so, the Bank has the right under the Plan to terminate the Plan, subject to the provisions of ERISA.

6. Tax Status

The Internal Revenue Service (IRS) determined and informed the Bank by a letter dated August 7, 2014 that the amended and restated Plan effective January 1, 2013 and related trust are designed in accordance with applicable sections of the Internal Revenue Code (IRC). The Plan has been amended since receiving the determination letter; however, the Plan Administrator believes that the Plan is designed and is being operated in compliance with the applicable requirements of the IRC. The related trust, therefore, is not subject to tax under present tax law.

Accounting principles generally accepted in the United States of America require Plan management to evaluate tax positions taken by the Plan and recognize a tax liability (or asset) if the Plan has taken an uncertain position that more likely than not would not be sustained upon examination by the IRS. The Plan is subject to routine audits by taxing jurisdictions; however, there currently are no audits for any tax periods in progress.

11

ERISA-Required Supplemental Schedule

12

Mercantile Bank of Michigan 401(k) Plan

Schedule H, Line 4i – Schedule of Assets (Held at End of Year)

EIN: 38-3360868 Plan Number: 001

December 31, 2022
(a)	(b)	(c)		(d)		(e)
	Identity of Issuer, Borrower, Lessor, or Similar Party	Description of Investment, Including Maturity Date, Rate of Interest, Collateral, Par, or Maturity Value**		Cost**		Current Value
	Mutual Funds	Shares
	Blackrock Equity Dividend Fund		179,487	**	$	3,279,229
	William Blair Large Cap RY		143,215	**		2,510,573
	Wasatch Cor Growth Institutional		14,420	**		949,612
	JPMorgan Mid Cap Value R6		24,797	**		850,074
	Hartford International Opportunities Y		72,694	**		1,190,736
	Delaware Small Cap Value R6		13,527	**		927,880
	T Rowe Price Mid Cap Growth Fund		27,387	**		2,434,715
	Vanguard 500 Index Admiral Shares		23,671	**		8,382,403
	Vanguard Mid Cap Index Admiral Shares		8,947	**		2,259,080
	Vanguard Small Cap Index Admiral Shares		22,639	**		1,990,930
	Delaware Emerging Market		23,320	**		398,085
	Matthews Pacific Tiger Fund		16,851	**		339,722
	Vanguard Total International Index Admiral		74,262	**		2,068,959
	T Rowe Price Balanced I Fund		70,791	**		744,022
	T Rowe Price Spectrum Conservative Allocation Fund		63,453	**		1,106,631
	T Rowe Price Retirement 2010 Fund		3,543	**		37,986
	T Rowe Price Retirement 2015 Fund		26,439	**		295,062
	T Rowe Price Retirement 2020 Fund		230,737	**		2,692,705
	T Rowe Price Retirement 2030 Fund		653,144	**		8,490,885
	T Rowe Price Retirement 2040 Fund		620,101	**		8,544,994
	T Rowe Price Retirement 2045 Fund		241,505	**		3,410,054
	T Rowe Price Retirement 2050 Fund		279,651	**		3,945,887
	T Rowe Price Retirement 2060 Fund		59,428	**		861,120
	Vanguard Intermediate Term Treasury Admiral		22,741	**		226,051
	Vanguard Short Term Treasury ADM		75,237	**		747,110
	Vanguard Short Term Invest Grade Fund Admiral		122,842	**		1,222,283
	Vanguard Total Bond Market Admiral		227,387	**		2,155,634
	Total Mutual Funds					62,062,422
	Common Stock
	Mercantile Bank Corporation		471,405	**		15,782,639
	Money Market Fund
	Northern Institutional Treasury Portfolio		2,433,662	**		2,433,662
	Total Investments, at fair value					80,278,723
*	Participant Loans	Interest rates from 4.25% to 9.25%, maturing at various dates through 2031			$	719,883

* Party-in-interest, as defined by ERISA.

** The cost of participant-directed investments is not required to be disclosed.

13

Exhibit to Report on Form 11-K

Exhibit No. Description

23.1 Consent of Independent Registered Public Accounting Firm.

14

Signature

The Plan. Pursuant to the requirements of the Securities Exchange Act of 1934, the trustees (or other persons who administer the employee benefit plan) have duly caused this annual report to be signed on its behalf by the undersigned hereunto duly authorized.

Mercantile Bank of Michigan 401(k) Plan

/s/Brett Hoover

Brett Hoover, Plan Administrator

Date: June 23, 2023         

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