| M C Bank & Trust Company | Morgan City, LA | $382.3M | 9 |
| M.Y. Safra Bank, FSB | New York, NY | $293.0M | 1 |
| M1 Bank | Clayton, MO | $1.0B | 2 |
| Mabrey Bank | Bixby, OK | $1.6B | 16 |
| Macatawa Bank | Holland, MI | $2.9B | 29 |
| Machias Savings Bank | Machias, ME | $2.3B | 15 |
| Macon Bank and Trust Company | Lafayette, TN | $666.0M | 7 |
| Madison Valley Bank | Ennis, MT | $235.6M | 5 |
| Magnolia Bank, Incorporated | Elizabethtown, KY | $439.2M | 3 |
| Magnolia State Bank | Bay Springs, MS | $414.5M | 8 |
| Magnolia State Bank | Eastman, GA | $166.2M | 5 |
| Magyar Bank | New Brunswick, NJ | $825.5M | 7 |
| Main Bank | Albuquerque, NM | $205.5M | 1 |
| Main Street Bank | Marlborough, MA | $1.4B | 6 |
| Main Street Bank Corp. | Wooster, OH | $1.2B | 19 |
| Maine Community Bank | Portland, ME | $2.3B | 23 |
| MainStreet Bank | Fairfax, VA | $1.8B | 6 |
| Mainstreet Community Bank of Florida | Deland, FL | $809.2M | 9 |
| Malaga Bank F.S.B. | Palos Verdes Peninsula, CA | $927.7M | 5 |
| Malvern Bank | Malvern, IA | $202.2M | 1 |
| Manasquan Bank | Manasquan, NJ | $2.8B | 15 |
| Manhattan Bank | Manhattan, MT | $231.8M | 4 |
| Manufacturers and Traders Trust Company | Buffalo, NY | $168.4B | 979 |
| Manufacturers Bank & Trust Company | Forest City, IA | $627.1M | 9 |
| Maple City Savings Bank, FSB | Hornell, NY | $115.5M | 3 |
| MapleMark Bank | Tulsa, OK | $825.5M | 2 |
| Marathon Bank | Wausau, WI | $183.4M | 5 |
| Marblehead Bank | Marblehead, MA | $225.6M | 3 |
| Marine Bank & Trust Company | Vero Beach, FL | $569.6M | 5 |
| Marion Center Bank | Indiana, PA | $383.1M | 7 |
| Marion Community Bank | Marion, AL | $317.4M | 6 |
| Marion County State Bank | Pella, IA | $550.2M | 5 |
| Marion State Bank | Marion, LA | $193.3M | 5 |
| Marion State Bank | Marion, TX | $125.6M | 1 |
| Marquette Bank | Chicago, IL | $1.8B | 22 |
| Marquette Savings Bank | Erie, PA | $1.0B | 11 |
| Marseilles Bank | Marseilles, IL | $64.8M | 2 |
| Martha's Vineyard Bank | Edgartown, MA | $1.1B | 10 |
| Mascoma Bank | Lebanon, NH | $2.6B | 26 |
| Maspeth Federal Savings and Loan Association | Maspeth, NY | $1.4B | 7 |
| MassMutual Private Wealth & Trust, FSB | Springfield, MA | $50.5M | 1 |
| Mauch Chunk Trust Company | Jim Thorpe, PA | $642.3M | 8 |
| Maverick Bank | Fort Davis, TX | $324.1M | 8 |
| Maxwell State Bank | Maxwell, IA | $23.6M | 1 |
| Mayville Savings Bank | Mayville, WI | $66.4M | 1 |
| McClain Bank | Purcell, OK | $242.0M | 4 |
| MCNB Bank and Trust Co. | Welch, WV | $303.9M | 7 |
| MCS Bank | Milroy, PA | $180.7M | 7 |
| Meade County Bank | Brandenburg, KY | $361.9M | 4 |
| Meadows Bank | Las Vegas, NV | $1.2B | 6 |
| Mechanics & Farmers Bank | Durham, NC | $421.2M | 8 |
| Mechanics Bank | Walnut Creek, CA | $14.0B | 112 |
| Mechanics Bank | Mansfield, OH | $751.6M | 9 |
| Mechanics Cooperative Bank | Taunton, MA | $657.2M | 10 |
| Medallion Bank | Salt Lake City, UT | $2.0B | 1 |
| Mediapolis Savings Bank | Mediapolis, IA | $229.0M | 5 |
| Mega Bank | San Gabriel, CA | $434.6M | 4 |
| Members Trust Company | Tampa, FL | $0.5M | 4 |
| Mercantile Bank | Grand Rapids, MI | $4.7B | 41 |
| Mercer County State Bank | Sandy Lake, PA | $528.8M | 12 |
| Mercer Savings Bank | Celina, OH | $142.4M | 4 |
| Merchants & Farmers Bank & Trust Company | Leesville, LA | $478.2M | 9 |
| Merchants & Farmers Bank of Greene County, Alabama | Eutaw, AL | $109.4M | 2 |
| Merchants & Marine Bank | Pascagoula, MS | $642.1M | 18 |
| Merchants & Planters' Bank | Newport, AR | $297.6M | 11 |
| Merchants and Farmers Bank | Dumas, AR | $231.8M | 3 |
| Merchants and Planters Bank | Raymond, MS | $174.9M | 6 |
| Merchants Bank | Winona, MN | $2.4B | 22 |
| Merchants Bank | Rugby, ND | $217.5M | 6 |
| Merchants Bank of Indiana | Carmel, IN | $12.8B | 7 |
| Merchants State Bank | Freeman, SD | $173.7M | 4 |
| Meredith Village Savings Bank | Meredith, NH | $1.3B | 15 |
| Meridian Bank | Wayne, PA | $2.1B | 6 |
| Merit Bank | Huntsville, AL | $384.4M | 1 |
| Merrick Bank | South Jordan, UT | $7.0B | 1 |
| Merrimack County Savings Bank | Concord, NH | $1.1B | 9 |
| Metairie Bank & Trust Company | Metairie, LA | $554.4M | 9 |
| Method Bank | Wyandotte, OK | $189.6M | 2 |
| Methuen Co-operative Bank | Methuen, MA | $125.9M | 1 |
| Metro Bank | Pell City, AL | $985.2M | 9 |
| Metro City Bank | Doraville, GA | $2.7B | 20 |
| Metropolitan Bank | Oakland, CA | $204.0M | 4 |
| Metropolitan Bank and Trust Company | New York, NY | $8.1M | 1 |
| Metropolitan Capital Bank & Trust | Chicago, IL | $223.1M | 1 |
| Metropolitan Commercial Bank | New York, NY | $6.8B | 8 |
| Mi Bank | Bloomfield Township, MI | $228.4M | 1 |
| Miami Savings Bank | Miamitown, OH | $103.8M | 3 |
| Mid America Bank | Jefferson City, MO | $808.0M | 11 |
| Mid Penn Bank | Millersburg, PA | $5.5B | 63 |
| Mid-America Bank | Baldwin City, KS | $390.7M | 6 |
| Mid-Missouri Bank | Springfield, MO | $828.2M | 13 |
| MidAmerica National Bank | Canton, IL | $583.1M | 6 |
| MidCountry Bank | Minneapolis, MN | $893.8M | 16 |
| Middlesex Federal Savings, F.A. | Somerville, MA | $589.8M | 4 |
| Middlesex Savings Bank | Natick, MA | $5.2B | 34 |
| Middletown State Bank | Middletown, IL | $35.9M | 3 |
| Middletown Valley Bank | Middletown, MD | $978.5M | 8 |
| MidFirst Bank | Oklahoma City, OK | $24.7B | 93 |
| Midland Community Bank | Kincaid, IL | $57.3M | 2 |
| Midland Federal Savings and Loan Association | Bridgeview, IL | $108.7M | 4 |
| Midland States Bank | Effingham, IL | $6.0B | 58 |
| MidSouth Bank | Dothan, AL | $669.3M | 13 |
| Midstates Bank | Council Bluffs, IA | $537.8M | 10 |
| Midwest Bank | Pierce, NE | $979.3M | 11 |
| Midwest Bank | Monmouth, IL | $550.9M | 8 |
| Midwest Bank | Detroit Lakes, MN | $710.1M | 7 |
| Midwest BankCentre | Lemay, MO | $2.5B | 18 |
| Midwest Heritage Bank, FSB | West Des Moines, IA | $362.3M | 9 |
| Midwest Independent BankersBank | Jefferson City, MO | $292.3M | 1 |
| Midwest National Bank | Sandoval, IL | $100.8M | 2 |
| Midwest Regional Bank | Clayton, MO | $982.9M | 7 |
| MidWestOne Bank | Iowa City, IA | $5.4B | 59 |
| Mifflinburg Bank and Trust Company | Mifflinburg, PA | $514.7M | 7 |
| Milestone Bank | Salt Lake City, UT | $328.6M | 1 |
| Milford Federal Bank | Milford, MA | $403.3M | 4 |
| Millbury National Bank | Millbury, MA | $113.9M | 1 |
| Millennial Bank | Leeds, AL | $166.8M | 2 |
| Millennium Bank | Des Plaines, IL | $659.6M | 3 |
| Millennium Bank | Ooltewah, TN | $465.2M | 10 |
| Millville Savings Bank | Millville, NJ | $142.7M | 2 |
| Milton Savings Bank | Milton, PA | $62.4M | 1 |
| Minnesota First Credit and Savings, Incorporated | Rochester, MN | $22.7M | 4 |
| Minnesota Lakes Bank | Delano, MN | $107.6M | 2 |
| Minnesota National Bank | Sauk Centre, MN | $241.9M | 3 |
| Minnstar Bank | Lake Crystal, MN | $166.1M | 2 |
| Minnwest Bank | Redwood Falls, MN | $2.6B | 36 |
| Minster Bank | Minster, OH | $683.4M | 7 |
| Mission Bank | Kingman, AZ | $177.8M | 3 |
| Mission Bank | Bakersfield, CA | $1.6B | 8 |
| Mission National Bank | San Francisco, CA | $194.4M | 1 |
| Mission Valley Bank | Sun Valley, CA | $599.6M | 3 |
| Mizrahi Tefahot Bank, Ltd. | Los Angeles, CA | $3.3B | 1 |
| Mizuho Bank (USA) | New York, NY | $5.2B | 1 |
| MNB Bank | Mccook, NE | $486.6M | 7 |
| Modern Bank | New York, NY | $533.9M | 2 |
| Monet Bank | Plano, TX | $2.5B | 7 |
| Monroe Federal Savings and Loan Association | Tipp City, OH | $127.3M | 4 |
| Monroe Savings Bank | Williamstown, NJ | $84.6M | 2 |
| Monson Savings Bank | Monson, MA | $675.5M | 5 |
| Montecito Bank & Trust | Santa Barbara, CA | $1.9B | 16 |
| Monterey County Bank | Monterey, CA | $193.3M | 4 |
| Montgomery Bank | Sikeston, MO | $1.0B | 12 |
| Morgan Stanley Bank | Salt Lake City, UT | $192.9B | 1 |
| Morgan Stanley Private Bank | Purchase, NY | $212.4B | 1 |
| Morganton Savings Bank, S.S.B. | Morganton, NC | $71.2M | 1 |
| Morgantown Bank & Trust Company, Incorporated | Morgantown, KY | $356.4M | 7 |
| Morris Bank | Dublin, GA | $1.3B | 9 |
| Morton Community Bank | Morton, IL | $4.6B | 50 |
| Mound City Bank | Platteville, WI | $446.5M | 6 |
| Mount Vernon Bank and Trust Company | Mount Vernon, IA | $150.2M | 1 |
| Mountain Commerce Bank | Knoxville, TN | $1.6B | 7 |
| Mountain Pacific Bank | Everett, WA | $655.7M | 5 |
| Mountain Valley Bank | Dunlap, TN | $209.0M | 5 |
| Mountain Valley Bank | Walden, CO | $448.5M | 7 |
| MountainOne Bank | North Adams, MA | $776.6M | 6 |
| Movement Bank | Danville, VA | $146.6M | 4 |
| MRV Banks | Sainte Genevieve, MO | $612.6M | 5 |
| Mt. McKinley Bank | Fairbanks, AK | $519.1M | 5 |
| Muenster State Bank | Muenster, TX | $186.7M | 2 |
| Municipal Trust and Savings Bank | Bourbonnais, IL | $283.5M | 2 |
| Murphy Bank | Fresno, CA | $295.4M | 2 |
| Murphy-Wall State Bank and Trust Company | Pinckneyville, IL | $180.0M | 6 |
| Mutual Federal Bank | Chicago, IL | $63.6M | 1 |
| Mutual Savings and Loan Association | Metairie, LA | $19.7M | 2 |
| Mutual Savings Association | Leavenworth, KS | $242.4M | 6 |
| Mutual Savings Bank | Franklin, IN | $244.3M | 4 |
| MutualOne Bank | Framingham, MA | $853.8M | 3 |
| MVB Bank, Inc | Fairmont, WV | $2.8B | 7 |