Methylmalonic Acid, Blood

Cleveland HeartLab M, Test

CPT Code: 83921
Order Code: C2405
ABN Requirement: No
Synonyms: MMA; Methylmalonate; MMA, Blood
Specimen: Serum
Volume:  2.0 mL
Minimum Volume:  0.7 mL
Container: Gel-barrier tube (SST, Tiger Top)


  1. Collect and label sample according to standard protocols.
  2. Gently invert tube 10 times immediately after draw. DO NOT SHAKE.
  3. Allow blood to clot 30 minutes.
  4. Centrifuge for 10 minutes.

Patient Preparation: Patients should not have already received Vitamin B12 replacement therapy.

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


Ambient (15-25°C): 7 days
Refrigerated (2-8°C): 30 days
Frozen (-20°C): 1 year
Deep Frozen (-70°C): 1 year

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

Methodology: High Performance Liquid Chromatography/Mass Spec (LC/MS)

Turn Around Time: 2 – 7 days

Reference Range:

Age nmol/L
All Ages 79.0-376.0

Urgent Values

Age nmol/L
All Ages >50,000

Intended Use: Confirmation of vitamin B12 deficiency when vitamin levels are equivocal.

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.