Immunoglobulin M (IgM)

Cleveland Heartlab I, Test


CPT Code: 82784
Order Code: 545
ABN Requirement: No
Synonyms: IgM
Specimen: Serum
Volume:  1.0 mL
Minimum Volume:  0.5 mL
Container: Gel-barrier tube (SST, Tiger Top)



  1. Collect and label sample according to standard protocols.
  2. Gently invert tube 5 times immediately after draw. DO NOT SHAKE.
  3. Let tube stand in a vertical position to allow blood to clot 30 minutes.
  4. Centrifuge for 10 minutes.

Transport: Store serum at 2-8°C after collection and ship the same day per packaging instructions included with the provided shipping box.


Ambient (15-25°C): 3 days
Refrigerated (2-8°C):
7 days
Frozen (-20°C):
90 days

Causes for Rejection: Specimens other than serum; improper labeling; samples not stored properly; samples older than stability limits; gross hemolysis; gross lipemia; gross icterus

Methodology: Immunoturbidimetric

Turn Around Time: 2 to 3 days

Reference Range:

Cord Blood6-25
1-28 days10-50
1-3 months10-72
4-6 months12-86
7-11 months13-120
1 year23-130
2 years25-135
3-5 years26-150
6-8 years25-150
9-11 years40-160
12-16 years41-170
≥17 years50-300

Clinical Significance: Increased IgM is associated with Waldenström’s macroglobulinemia, infectious mononucleosis, viral infections, nephrotic syndrome, and estrogen therapy; decreased IgM is found in selective IgM deficiency, Bruton’s Disease, and acquired immune deficiency.

The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.