Note 14 - Regulatory Matters (Tables)

9 Months Ended

Sep. 30, 2026

Notes Tables

Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block]

																		Minimum Required
																		to be Well
										Minimum Required								Capitalized Under
										for Capital								Prompt Corrective
		Actual								Adequacy Purposes								Action Regulations
(Dollars in thousands)		Amount				Ratio				Amount				Ratio				Amount				Ratio
September 30, 2026
Total capital (to risk weighted assets)
Consolidated		$	917,167				14.6	%		$	502,714				8.0	%		$ NA				NA%
Mercantile Bank			791,783				13.4				473,476				8.0				591,845				10.0
Eastern Michigan Bank			66,569				23.9				22,293				8.0				27,866				10.0
Tier 1 capital (to risk weighted assets)
Consolidated			768,377				12.2				377,035				6.0			NA				NA
Mercantile Bank			735,149				12.4				355,107				6.0				473,476				8.0
Eastern Michigan Bank			64,326				23.1				16,720				6.0				22,293				8.0
Common equity tier 1 (to risk weighted assets)
Consolidated			718,922				11.4				282,777				4.5			NA				NA
Mercantile Bank			735,149				12.4				266,330				4.5				384,699				6.5
Eastern Michigan Bank			64,326				23.1				12,540				4.5				18,113				6.5
Tier 1 capital (to average assets)
Consolidated			768,377				11.1				276,647				4.0			NA				NA
Mercantile Bank			735,149				11.6				254,361				4.0				317,952				5.0
Eastern Michigan Bank			64,326				12.0				21,511				4.0				26,889				5.0

December 31, 2025
Total capital (to risk weighted assets)
Consolidated		$	859,158				14.4	%		$	477,044				8.0	%		$ NA				NA%
Mercantile Bank			775,664				13.8				449,498				8.0				561,873				10.0
Eastern Michigan Bank			58,893				20.2				23,335				8.0				29,168				10.0
Tier 1 capital (to risk weighted assets)
Consolidated			709,058				11.9				357,783				6.0			NA				NA
Mercantile Bank			717,619				12.8				337,124				6.0				449,498				8.0
Eastern Michigan Bank			56,495				19.4				17,501				6.0				23,335				8.0
Common equity tier 1 (to risk weighted assets)
Consolidated			660,117				11.1				268,337				4.5			NA				NA
Mercantile Bank			717,619				12.8				252,843				4.5				365,217				6.5
Eastern Michigan Bank			56,495				19.4				13,126				4.5				18,960				6.5
Tier 1 capital (to average assets)
Consolidated			709,058				11.4				249,580				4.0			NA				NA
Mercantile Bank			717,619				11.5				248,738				4.0				310,922				5.0
Eastern Michigan Bank			56,495				11.5				19,621				4.0				24,527				5.0