| Y 3.M 26 | James Madison Memorial Commission (1960-1972) |
| Y 3.M 31 | National Commission for Manpower Policy (1973- 1978) |
| Y 3.M 33 | Maritime Advisory Committee (1964-1968) |
| Y 3.M 33/2 | Marihuana and Drug Abuse Commission (1970-?) |
| Y 3.M 33/3 | Marine Mammal Commission (1972- ) |
| Y 3.M 35 | John Marshall Bicentennial Celebration Commission (1954-1955) |
| Y 3.M 41 | National Commission on Materials Policy (1970-1973) |
| Y 3.M 46/2 | Council on Graduate Medical Education (1987-1996) |
| Y 3.M 46/3 | Medicare Payment Advisory Commission (1997- ) |
| Y 3.M 46/4 | Medicaid and CHIP Payment Access Commission (MACPAC) (2010- ) |
| Y 3.M 53 | Mediation Commission (1917-1918) (check stem; M43?) |
| Y 3.M 53 | Merchant Marine Commission (1904-1905) |
| Y 3.M 53/2 | Merchant Marine and Defense Commission |
| Y 3.M 56 | United States Metric Board (1975-1982) |
| Y 3.M 58 | Migratory Bird Conservation Commission (1929- ) |
| Y 3.M 58/2 | Commission for the Study of International Migration and Cooperative Economic Development (1986-1990) |
| Y 3.M 58/3 | National Commission on Migrant Education |
| Y 3.M 59 | Commission to Examine the Military Academy (1860) |
| Y 3.M 66 | Federal Mine Safety and Health Review Commission (1978- ) |
| Y 3.M 66/2 | Minimum Wage Study Commission (1977-1981) |
| Y 3.M 69 | Missouri Basin Inter-Agency Committee (1945-1972) |
| Y 3.M 69/2 | Missouri River Basin Commission (1972-1981) |
| Y 3.M 74 | Monetary Commission (1876) |
| Y 3.M 74/2 | Monitored Retrievable Storage Review Commission (1987-1989) |
| Y 3.M 84 | Mortgage Interest Rates Commission (1968-1969) |
| Y 3.M 85 | Interagency Task Force on Motor Vehicle Goals Beyond 1980 (1975-1976) |
| Y 3.M 85/2 | Motor Carrier Ratemaking Study Commission (1980-1983) |
| Y 3.M 97 | Muscle Shoals Commission (1931) |
