{"id":"igm","name":"Immunoglobulin M (IgM)","shortName":"IgM","aliases":["Immunoglobulin M","IgM","IgM, Quantitative","IgM Serum","IgM, Total","Immunoglobulin M, Qn, Serum","Total IgM","Immunoglobulin M (IgM), Serum","IgM, Serum","Serum IgM","IgM Quant","Immunoglobulin M, Quantitative","Inmunoglobulina M","Immunglobulin M"],"abbreviations":["IgM"],"loinc":[{"code":"2472-9","primary":true}],"specimen":"serum-or-plasma","units":[{"ucum":"mg/dL","display":"mg/dL"},{"ucum":"g/L","display":"g/L"},{"ucum":"mg/L","display":"mg/L"}],"referenceRanges":[{"population":"Men, 20–70","low":20,"high":172,"unit":"mg/dL","unitDisplay":"mg/dL","note":"Labcorp interval for males 20 to 70 (test 001792), from its pediatric reference ranges document. Labcorp prints 26–217 mg/dL for females, and women tend to run higher. Mayo (37–286 mg/dL) and ARUP (35–263) print one interval for all adults, and ABIM lists 45–150. Use the interval printed on your own report first.","sources":[{"title":"Pediatric Testing Reference Ranges (includes adult intervals for Labcorp tests 001776, 001784, 001792 and 001834)","url":"https://www.labcorp.com/content/dam/labcorp/drupal/178250_DX_TL_PediatricTestRef_Final.pdf","publisher":"Labcorp Diagnostics"}]},{"population":"Women, 20–70","low":26,"high":217,"unit":"mg/dL","unitDisplay":"mg/dL","note":"Labcorp interval for females 20 to 70 (test 001792).","sources":[{"title":"Pediatric Testing Reference Ranges (includes adult intervals for Labcorp tests 001776, 001784, 001792 and 001834)","url":"https://www.labcorp.com/content/dam/labcorp/drupal/178250_DX_TL_PediatricTestRef_Final.pdf","publisher":"Labcorp Diagnostics"}]},{"population":"18+","low":37,"high":286,"unit":"mg/dL","unitDisplay":"mg/dL","note":"Mayo Clinic Laboratories interval for all adults 18 and older (nephelometry), with no sex split. ARUP prints 35–263 mg/dL for ages 19 and up (immunoturbidimetry) and ABIM lists 45–150 mg/dL. The spread between labs is wide, so use the interval on your own report first.","sources":[{"title":"Immunoglobulin M (IgM), Serum (test ID IGM)","url":"https://www.mayocliniclabs.com/test-catalog/overview/8158","publisher":"Mayo Clinic Laboratories"},{"title":"Immunoglobulins (IgA, IgG, IgM), Quantitative (test 0050630)","url":"https://ltd.aruplab.com/Tests/Pub/0050630","publisher":"ARUP Laboratories"},{"title":"ABIM Laboratory Test Reference Ranges, January 2026","url":"https://www.abim.org/Media/bfijryql/laboratory-reference-ranges.pdf","publisher":"American Board of Internal Medicine","year":2026}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"The first antibody your body makes against a new germ. Reported in mg/dL in the US and in g/L in many other countries.","url":"https://bloodtesttracker.com/markers/igm","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}