- Lufkin (LFK)
- Lumberton (LBT)
- Lynchburg (LYH)
- Macon (MCN)
- Madison (MSN)
- Mammoth Lakes (MMH)
- Manassas (MNZ)
- Manchester (MHT)
- Manhattan (MHK)
- Mansfield (MFD)
- Marathon (MTH)
- Marietta (MGE)
- Marion (MWA)
- Martinsburg (MRB)
- Marysville (MYV)
- Mason City (MCW)
- Massena (MSS)
- Mc Alester (MLC)
- McAllen (MFE)
- McCall (MYL)
- McComb (MCB)
- McCook (MCK)
- McGrath (MCG)
- Medford (MFR)
- Mekoryuk (MYU)
- Melbourne (MLB)
- Memphis (MEM)
- Merced (MCE)
- Merced (MER)
- Mercury (DRA)
- Meridian (MEI)
- Mesa (AZA)
- Mesquite (MFH)
- Metlakatla (ANN)
- Miami (MIA)
- Miami (OPF)
- Miami (TMB)
- Michigan City (MGC)
- Midland (MAF)
- Miles City (MLS)
- Millington (NQA)
- Millville (MIV)
- Milton (NSE)
- Milwaukee (MKE)
- Mineral Wells (MWL)
- Minneapolis (MSP)
- Minot (MIB)
- Minot (MOT)
- Missoula (MSO)
- Moab (CNY)
- Mobile (BFM)
- Mobile (MOB)
- Mobridge (MBG)
- Modesto (MOD)
- Mojave (MHV)
- Moline (MLI)
- Monroe (MLU)
- Monterey (MRY)
- Montgomery (MGM)
- Montgomery (MXF)
- Montrose (MTJ)
- Morgantown (MGW)
- Morristown (MMU)
- Moselle (PIB)
- Moses Lake (MWH)
- Mosinee (CWA)
- Mount Clemens (MTC)
- Mountain Home (MUO)
- Mountain Home (WMH)
- Mountain View (NUQ)
- Muncie (MIE)
- Murphysboro (MDH)
- Muscle Shoals (MSL)
- Muskegon (MKG)
- Myrtle Beach (MYR)
- Nantucket (ACK)
- Naples (APF)
- Nashville (BNA)
- Needles (EED)
- Nenana (ENN)
- New Bedford (EWB)
- New Bern (EWN)
- New Haven (HVN)
- New Iberia (ARA)
- New Orleans (MSY)
- New Orleans (NBG)
- New Orleans (NEW)
- New Richmond (RNH)
- New York (JFK)
- New York (LGA)
- Newark (EWR)
- Newburgh (SWF)
- Newport (NPT)
- Newport (ONP)
- Newport News (PHF)
- Newport News (Fort Eustis) (FAF)
- Niagara Falls (IAG)
- Nogales (OLS)
- Nome (OME)
- Norfolk (NGU)
- Norfolk (OFK)
- Norfolk (ORF)
- North Bend (OTH)
- North Kingstown (NCO)
- North Myrtle Beach (CRE)
- North Platte (LBF)
- Northway (ORT)
- Norwood (OWD)
- Nuiqsut (NUI)
- Oak Harbor (NUW)
- Oakland (OAK)
- Ocean City (OCE)
- Oceanside (OCN)
- Ogden (HIF)
- Ogden (OGD)
- Ogdensburg (OGS)
- Oklahoma City (OKC)
- Oklahoma City (TIK)
- Olympia (OLM)
- Omaha (OFF)