    <SEC-DOCUMENT>0001437749-20-019043-index.html : 20200831
    <SEC-HEADER>0001437749-20-019043.hdr.sgml : 20200831
    <ACCEPTANCE-DATETIME>20200831172145
    ACCESSION NUMBER:		0001437749-20-019043
    CONFORMED SUBMISSION TYPE:	S-3D
    PUBLIC DOCUMENT COUNT:		9
    FILED AS OF DATE:		20200831
    DATE AS OF CHANGE:		20200831
    EFFECTIVENESS DATE:		20200831

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			MERCANTILE BANK CORP
    		CENTRAL INDEX KEY:			0001042729
    		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
    		IRS NUMBER:				383360865
    		STATE OF INCORPORATION:			MI
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		S-3D
    		SEC ACT:		1933 Act
    		SEC FILE NUMBER:	333-248512
    		FILM NUMBER:		201152586

    	BUSINESS ADDRESS:
    		STREET 1:		310 LEONARD STREET NW
    		CITY:			GRAND RAPIDS
    		STATE:			MI
    		ZIP:			49504
    		BUSINESS PHONE:		616 406-3000

    	MAIL ADDRESS:
    		STREET 1:		310 LEONARD STREET NW
    		CITY:			GRAND RAPIDS
    		STATE:			MI
    		ZIP:			49504
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>S-3D
    <SEQUENCE>1
    <FILENAME>mbwm20200826_s3d.htm
    <DESCRIPTION>FORM S-3D
    <TEXT>
    Document 1 - file: mbwm20200826_s3d.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-5
    <SEQUENCE>2
    <FILENAME>ex_201785.htm
    <DESCRIPTION>EXHIBIT 5
    <TEXT>
    Document 2 - file: ex_201785.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-23.2
    <SEQUENCE>3
    <FILENAME>ex_202285.htm
    <DESCRIPTION>EXHIBIT 23.2
    <TEXT>
    Document 3 - file: ex_202285.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.A
    <SEQUENCE>4
    <FILENAME>ex_201799.htm
    <DESCRIPTION>EXHIBIT 99(A)
    <TEXT>
    Document 4 - file: ex_201799.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>5
    <FILENAME>a1.jpg
    <TEXT>
    Document 5 - file: a1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>6
    <FILENAME>a2.jpg
    <TEXT>
    Document 6 - file: a2.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>7
    <FILENAME>debit1.jpg
    <TEXT>
    Document 7 - file: debit1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>8
    <FILENAME>enroll1.jpg
    <TEXT>
    Document 8 - file: enroll1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>9
    <FILENAME>enroll2.jpg
    <TEXT>
    Document 9 - file: enroll2.jpg

    </DOCUMENT>
    </SEC-DOCUMENT>