| 94012 | M-Malonic Acid [MMA] |
| 91566 | MAG Ab IgM |
| 2042 | Magnesium |
| 9669 | Magnesium, RBC |
| 91159 | Magnesium, Urine |
| 80206 | Maize [IgE], Corn Pollen [IgE] |
| 91572 | Malaria Abs, IgG |
| 91160 | Manganese |
| 80100 | Maple [IgE] |
| 91317 | Marijuana, GCMS |
| 80265 | Marshelder [IgE] |
| 91281 | Maternal AFP [Only] |
| 91011 | Maternal Quad Marker |
| 93638 | Maternal Screen #1 |
| 93639 | Maternal Screen #2 |
| 80208 | Meadow Fescue [IgE] |
| 94010 | Measles |
| 9573 | Meconium Analysis |
| 2095 | Medical Alcohol |
| 9940 | Medical Drug Screen [Urine] |
| 2140 | Megaloblastic Anemia Panel |
| 80046 | Melons [IgE] |
| 4083 | Meningitis DAT |
| 2137 | Mephobarbital |
| 91354 | Meprobamate |
| 93370 | Mercury, Blood |
| 91162 | Mercury, Urine |
| 91144 | Metanephrines, Plasma (Free) |
| 91163 | Metanephrines, Urine Fractionated |
| 93540 | Methadone Quantitative |
| 91314 | Methadone, GCMS |
| 4041 | Methicillin Resistant Staph |
| 91164 | Methotrexate |
| 91341 | Methsuximide |
| 94052 | Methylenetetrahydrofolate Reductase |
| 94012 | Methylmalonic Acid |
| 91574 | Mexiletine |
| 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] |
| 2370 | Microsomal Antibody |
| 80001 | Milk, Cows [IgE] |
| 91354 | Miltown |
| 2333 | Mitochondrial Antibody |
| 94012 | MMA |
| 80824 | Mold Panel |
| 2335 | Mononucleosis Screen |
| 1856 | Mononucleosis Viral Panel |
| 80109 | Mountain Juniper [IgE] |
| 2461 | MPO |
| 4041 | MRSA Screen |
| 91166 | MS Panel |
| 94052 | MTHFR Mutation |
| 80354 | Mucor racemosis [IgE] |
| 80250 | Mugwort [IgE] |
| 80114 | Mulberry [IgE] |
| 91166 | Multiple Sclerosis Panel |
| 91167 | Mumps Virus Antibody, IgG |
| 91168 | Mumps Virus Antibody, IgM |
| 80059 | Mustard [IgE] |
| 93630 | Myasthenia Gravis Panel |
| 4204 | Mycobacteria Culture |
| 91350 | Mycobacteria Culture (Blood) |
| 91444 | Mycophenolic Acid |
| 91169 | Mycoplasma pneumoniae Antibodies, IgG/IgM |
| 91508 | Mycoplasma pneumoniae by PCR |
| 93085 | Mycoplasma, IgG |
| 91566 | Myelin Associated Glycoprotein Ab, IgM |
| 93625 | Myelin Basic Protein, CSF |
| 2461 | Myeloperoxidase |
| 2272 | Myoglobin |
| 91330 | Myoglobin, Urine Quantitative |
| 3013 | Myoglobin, Urine [Qual] |
| 2115 | Mysoline |