- Menninger, Karl A. (Karl Augustus), 1893-19901
- Menominee Indian Tribe of Wisconsin1
- Menominee Indians3
- Merritt, T. Allen, 1946-1
- Mescalero Apache Tribe of the Mescalero Reservation, New Mexico1
- Miami Tribe of Oklahoma14
- Miami Tribe of Oklahoma of Oklahoma5
- Modoc Indians1
- Modoc Tribe1
- Modoc Tribe of Oklahoma of Oklahoma1
- Moore, Arch A., Jr. (Arch Alfred), 1923-20151
- Murphy, Austin J.2
- Muscogee (Creek) Nation1
- Muscogee (Creek) Nation, Oklahoma10
- National Center for Medical Rehabilitation Research (U.S.)1
- National Council on U.S.-Arab Relations1
- National Institutes of Health (U.S.)2
- National Organization on Disability (U.S.)2
- National Rehabilitation Hospital (Washington, D.C.)2
- Navajo Indians3
