| MACNUT | Macadamia Nut, IgE | — |
| MACKRL | Mackerel IgE | — |
| MCRAD | Macroamylase Determination | — |
| MPRL | Macroprolactin | — |
| MG | Magnesium | Colorimetric Method |
| MGF | Magnesium, Fecal | — |
| MRBC | Magnesium, RBC | — |
| UMGB | Magnesium, Urine, 24 Hour | — |
| UMGS | Magnesium, Urine, Random | — |
| PSPCR | Malaria (Plasmodium Species) by PCR | — |
| TSTP | Male Testosterone Panel | Electrochemiluminescence Immunoassay |
| MHPS | Malignant Hyperthermia Panel, Sequencing | — |
| MNB | Manganese, Blood | — |
| MAN | Manganese, Serum | — |
| WBM | Manganese, Whole Blood | — |
| MANGO | Mango IgE | — |
| MBLS | Mannose Binding Lectin | — |
| FBN1 | Marfan Syndrome, FBN1 Sequencing | — |
| MSSI1 | Maternal Serum Screening, Integr Spec #1 PAPP-A, NT | — |
| MSSI2 | Maternal Serum Screening, Integrated Spec #2 | — |
| MMP9A | Matrix Metalloproteinase-9 (MMP-9) | — |
| RUOL | Measles (Rubeola) Antibody, IgG | — |
| MEAM | Measles (Rubeola) Antibody, IgM | — |
| MVNAAT | Measles Virus by Qualitative NAAT | — |
| MEASLE | Measles Virus PCR (Swab or Urine) | — |
| MMRRPS | Measles/Mumps/Rubella Immunity, Qualitative | — |
| MMRVI | Measles/Mumps/Rubella/Varicella Zoster Immunity Qualitative | — |
| MMRVPAN | Measles/Mumps/Rubella/VZV Quant Antibody Assessment Panel, IgG | — |
| MDS11 | Meconium Drug Screen Panel 11 | — |
| MDSPR | Meconium Drug Screen Panel 12 w/Alcohol | — |
| MSHA | Melanocyte Stimulation Hormone, Alpha (a-MSH) | — |
| MLTNP | Melatonin, Serum or Plasma | — |
| MEEP | Meningitis/Encephalitis Panel | — |
| FMEP | Meperidine (Demerol) and Normeperidine, Serum | — |
| CDMEPE | Meperidine & Metabolite, UR, Quant | — |
| MPDN | Meperidine and Metabolite, Serum | — |
| MEPURQ | Meperidine, Urine w/reflex to Quantitation | — |
| HG | Mercury, Blood | — |
| URHG | Mercury, Random or 24 Hour Urine | — |
| METN | Metanephrines Urine Total/Fractionated Random or 24 Hr. | — |
| MFPF | Metanephrines, Fractionated, Plasma Free | — |
| MTFRM | Metformin | — |
| METHM | Methadone & Metabolite, Urine Quantitation | — |
| MCUN | Methadone Screen & Confirmation, Urine | — |
| METHS | Methadone, Serum/Plasma | — |
| METHME | Methamphetamine and Metabolite, Blood | — |
| MEOH | Methanol, Blood | — |
| MHGV | Methemoglobin | — |
| METX | Methotrexate | — |
| NMES | Methsuximide (Celontin) | — |
| MMASR | Methylmalonic Acid (MMA) Serum Quantitative | — |
| MMMAL | Methylmalonic Acid (MMA) Urine Quantitative | — |
| MCRT | Microalbumin/Creatinine Ratio, 24 Hour Timed Urine | Immunoturbidimetric Assay |
| MCRR | Microalbumin/Creatinine Ratio, Urine | Immunoturbidimetric Assay |
| MICSPOR | Microsporidia by PCR | — |
| MILK | Milk IgE | — |
| AMIT | Mitochondrial (M2) Antibody, IgG | — |
| MTDNA | Mitochondrial Disorders Panel (mtDNA & Nuclear Genes) | — |
| MITOSP | Mitotane, Serum or Plasma | — |
| MOLYBD | Molybdenum Quant, Serum or Plasma | — |
| QMPSS | Monoclonal Gammopathy | — |
| MPSU | Monoclonal Protein Study, 24 Hr. Urine | — |
| MONX | Mononucleosis | Direct Solid-Phase Immunoassay |
| MORPU | Morphine Level, Urine | — |
| FMNPP | Motor Neuropathy Panel | — |
| MSNER | Motor Sensory Eval | — |
| MDS2 | Movement Disorder, Autoimmune Eval, Serum | — |
| MPLMUT | MPL Mutation Detection | — |
| MRSANS | MRSA by PCR, Nasal | — |
| MRSCU | MRSA Culture | — |
| MTHF | MTHFR DNA Analysis | — |
| MUGWRT | Mugwort IgE | — |
| MEN1 | Multiple Endocrine Neoplasia Type 1 (MEN1) Sequencing | — |
| MSPL | Multiple Sclerosis Panel | — |
| MUMPG | Mumps Ab IgG | — |
| MUMPQT | Mumps IgG, Quantitative | — |
| MUMPM | Mumps IgM Abs | — |
| MUMPCR | Mumps Virus by PCR | — |
| MUSHRM | Mushroom IgE | — |
| MUSK | MuSK Antibody | — |
| MUSTRD | Mustard IgE | — |
| FMGRP | Myasthenia Gravis Reflex Panel | — |
| TBAPR | Mycobacterium tuberculosis Amplified Direct Detection | — |
| MYPH | Mycophenolic Acid (Cellcept) | — |
| MYCOPC | Mycoplasma & Ureaplasma Species (Urogenital) by PCR | — |
| MGEN | Mycoplasma genitalium rRNA | — |
| AMGEN | Mycoplasma genitalium, Transcription-Mediated Amplification, Urine or Urogenital Swab | — |
| MYAGM | Mycoplasma pneumoniae Antibodies, IgG & IgM | — |
| MYABG | Mycoplasma pneumoniae Antibody, IgG | — |
| MYPM | Mycoplasma pneumoniae Antibody, IgM | — |
| MYCPNA | Mycoplasma Pneumoniae by PCR | — |
| MYD88 | MYD88 Mutation Detection, Peripheral blood | — |
| MAGAB | Myelin Associated Glycoprotein (MAG) Antibody, IgM | — |
| MYBP | Myelin Basic Protein | — |
| MOGAG | Myelin Oligodendrocyte Glycoprotein (MOG) Ab, IgG w/reflex | — |
| MOGFS | Myelin Oligodendrocyte Glycoprotein IgG (FACS) Assay, Serum | — |
| MYMPB | Myeloid Mutation Panel, Blood | — |
| MYELOB | Myeloma Screening Panel | — |
| MAS1 | Myelopathy, Autoimmune/Paraneoplastic Eval, Serum | — |
| MPO | Myeloperoxidase (MPO) Antibody | — |
| MPNPB | Myeloproliferative Neoplasm (MPN) Panel/Peripheral Blood | — |
| MYOAST | Myocardial Antibody Screen w/reflex to Titer | — |
| MYOGS | Myoglobin | — |
| UMYG | Myoglobin, Urine | — |
| FMYO3 | MyoMarker 3 Profile | — |
