| MABC Federal Credit Union | Pennsylvania |
| Mabrey Bank | Oklahoma |
| Macatawa Bank | Michigan |
| MAC Federal Credit Union | Alaska |
| Machias Savings Bank | Maine |
| Machinists-Boilermakers Federal Credit Union | Oregon |
| Mackinac Savings Bank | Florida |
| Macon-Atlanta State Bank | Missouri |
| Macon Bank & Trust Company | Tennessee |
| Macon-Bibb Employees Credit Union | Georgia |
| Macon Firemen's Credit Union | Georgia |
| Macon Police Credit Union | Georgia |
| Macon Water Works Credit Union | Georgia |
| Madco Credit Union | Illinois |
| Madison Bank of Maryland | Maryland |
| Madison County Bank | Nebraska |
| Madison County Community Bank | Florida |
| Madison County Federal Credit Union | Indiana |
| Madison Credit Union | Wisconsin |
| Madison Education Association Credit Union | Florida |
| Madison Fire Department Credit Union | Wisconsin |
| MA Ford Employees Credit Union | Iowa |
| Magnify Credit Union | Florida |
| Magnolia Bank | Kentucky |
| Magnolia Federal Credit Union | Mississippi |
| Magnolia State Bank | Mississippi |
| Magyar Bank | New Jersey |
| Mahopac Bank | New York |
| Main Bank | New Mexico |
| Maine Family Federal Credit Union | Maine |
| Maine Highlands Federal Credit Union | Maine |
| Maine Media Federal Credit Union | Maine |
| Maine Savings Federal Credit Union | Maine |
| Maine State Credit Union | Maine |
| Mainland Bank | Texas |
| MainSource Bank | Indiana |
| Main Street Bank | Michigan |
| Mainstreet Bank | Missouri |
| MainStreet Bank | Virginia |
| Main Street Bank Corp. | West Virginia |
| Mainstreet Community Bank of Florida | Florida |
| Mainstreet Federal Credit Union | Kansas |
| Malaga Bank F.S.B. | California |
| Malden City Employees Credit Union | Massachusetts |
| Malden Teachers Federal Credit Union | Massachusetts |
| Malheur Federal Credit Union | Oregon |
| Malvern Federal Savings Bank | Pennsylvania |
| Malvern Trust & Savings Bank | Iowa |
| MAMTA Federal Credit Union | New York |
| Manasquan Bank | New Jersey |
| Manatee Community Federal Credit Union | Florida |
| Manatrol Division Employees Credit Union | Ohio |
| Manchester Federal Credit Union | Massachusetts |
| Manchester Municipal Federal Credit Union | Connecticut |
| Manhattan Bank | Montana |
| Manistee Federal Credit Union | Michigan |
| Manistee Public Employees Credit Union | Michigan |
| Manistique Federal Credit Union | Michigan |
| Manor Bank | Pennsylvania |
| Mansfield Co-operative Bank | Massachusetts |
| Manson State Bank | Iowa |
| Manufacturers Bank | California |
| Manufacturers Bank & Trust Company | Iowa |
| Manville Area Federal Credit Union | New Jersey |
| Maple Bank | Minnesota |
| Maple City Savings Bank | New York |
| Maple Federal Credit Union | Louisiana |
| Mapleton Public Schools Federal Credit Union | Colorado |
| Maquoketa State Bank | Iowa |
| Marathon County Employees Credit Union | Wisconsin |
| Marathon Republic Federal Credit Union | Texas |
| Marathon Savings Bank | Wisconsin |
| Marblehead Bank | Massachusetts |
| Marblehead Municipal Federal Credit Union | Massachusetts |
| Marin County Federal Credit Union | California |
| Marine Bank | Illinois |
| Marine Bank and Trust | Illinois |
| Marine Bank & Trust Company | Florida |
| Marine Credit Union | Wisconsin |
| Marine Federal Credit Union | North Carolina |
| Mariners Bank | New Jersey |
| Marion and Polk Schools Credit Union | Oregon |
| Marion Bank & Trust Company | Alabama |
| Marion Center Bank | Pennsylvania |
| Marion Community Credit Union | Ohio |
| Marion County Savings Bank | Illinois |
| Marion County School Employees Federal Credit Union | West Virginia |
| Marion County State Bank | Iowa |
| Marion State Bank | Louisiana |
| Marion State Bank | Texas |
| Marisol Federal Credit Union | Arizona |
| Markesan State Bank | Wisconsin |
| Market USA Federal Credit Union | Maryland |
| Marlborough Savings Bank | Massachusetts |
| Marlin Business Bank | Utah |
| Maroon Financial Credit Union | Illinois |
| Marquette Bank | Illinois |
| Marquette Community Federal Credit Union | Michigan |
| Marquette Farmers State Bank of Marquette | Kansas |
| Marquette Savings Bank | Pennsylvania |