<ACCESSION-NUMBER>0001437749-18-018324 <TYPE>8-K <PUBLIC-DOCUMENT-COUNT>3 <PERIOD>20181016 <ITEMS>2.02 <ITEMS>9.01 <FILING-DATE>20181016 <DATE-OF-FILING-DATE-CHANGE>20181016 <FILER> <COMPANY-DATA> <CONFORMED-NAME>MERCANTILE BANK CORP <CIK>0001042729 <ASSIGNED-SIC>6022 <IRS-NUMBER>383360865 <STATE-OF-INCORPORATION>MI <FISCAL-YEAR-END>1231 </COMPANY-DATA> <FILING-VALUES> <FORM-TYPE>8-K <ACT>34 <FILE-NUMBER>000-26719 <FILM-NUMBER>181123574 </FILING-VALUES> <BUSINESS-ADDRESS> <STREET1>310 LEONARD STREET NW <CITY>GRAND RAPIDS <STATE>MI <ZIP>49504 <PHONE>616 406-3000 </BUSINESS-ADDRESS> <MAIL-ADDRESS> <STREET1>310 LEONARD STREET NW <CITY>GRAND RAPIDS <STATE>MI <ZIP>49504 </MAIL-ADDRESS> </FILER>