| 91165 | M-Malonic Acid [MMA] |
| 2042 | Magnesium |
| 91159 | Magnesium, Urine |
| 91160 | Manganese |
| 91317 | Marijuana, GCMS |
| 91281 | Maternal AFP [Only] |
| 91011 | Maternal Quad Marker |
| 91161 | Measles |
| 2140 | Megaloblastic Anemia Panel |
| 4083 | Meningitis DAT |
| 2137 | Mephobarbital |
| 91354 | Meprobamate |
| 93370 | Mercury, Blood |
| 91162 | Mercury, Urine |
| 91144 | Metanephrines, Plasma (Free) |
| 91163 | Metanephrines, Urine Fractionated |
| 91314 | Methadone, GCMS |
| 91164 | Methotrexate |
| 91341 | Methsuximide |
| 91405 | Methylenetetrahydrofolate Reductase |
| 91165 | Methylmalonic Acid |
| 2042 | MG |
| 91159 | MG, Urine |
| 91209 | MHA-TP |
| 1112 | Microalbumin, 24 Hour |
| 1113 | Microalbumin, Urine (Random) |
| 1113 | Microalbumin/Creatinine Ratio, Urine (Random) |
| 91029 | Microglobulin, Beta 2 [Serum] |
| 91030 | Microglobulin, Beta 2 [Urine] |
| 1416 | Microsomal Ab |
| 2370 | Microsomal Antibody |
| 91354 | Miltown |
| 2333 | Mitochondrial Antibody |
| 91165 | MMA |
| 2335 | Mononucleosis Screen |
| 1856 | Mononucleosis Viral Panel |
| 2461 | MPO |
| 91166 | MS Panel |
| 91405 | MTHFR Mutation |
| 91166 | Multiple Sclerosis Panel |
| 91167 | Mumps Virus Antibody, IgG |
| 91168 | Mumps Virus Antibody, IgM |
| 4204 | Mycobacteria Culture |
| 91350 | Mycobacteria Culture (Blood) |
| 91444 | Mycophenolic Acid |
| 91169 | Mycoplasma pneumoniae Antibodies, IgG/IgM |
| 91254 | Mycoplasma Pneumoniae, Culture |
| 93085 | Mycoplasma, IgG |
| 2461 | Myelopperoxidase |
| 2272 | Myoglobin |
| 91330 | Myoglobin, Urine Quantitative |
| 3013 | Myoglobin, Urine [Qual] |
| 2115 | Mysoline |