Gamma Glutamyl Transferase (GGT)

Cleveland Heartlab G, Test

CPT Code: 82977
Order Code: 482
ABN Requirement:  No
Synonyms: γ-glutamyl transferase; Gamma-glutamyl Transpeptidase; GGTP; Gamma GT; GTP; GGT
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. Allow blood to clot 30 minutes.
  4. Centrifuge for 10 minutes.

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): 7 days
Frozen (-20°C): 28 days

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

Methodology: Enzymatic

Turn Around Time: 1 to 5 days

Reference Range:

Age Male U/L Female U/L
<6 Months 12-122 15-132
6-11 Months ≤39 ≤39
1-12 Years 3-22 3-22
13-15 Years 8-32 7-18
16-19 Years 9-31 6-26
20-29 Years 3-70 3-40
30-39 Years 3-90 3-50
40-54 Years 3-95
40-49 Years 3-55
50-59 Years 3-70
55-59 Years 3-85
≥60 Years 3-70 3-65

Intended Use: A g-glutamyl transferase test can be used to differentiate between liver and bone disease as a cause for elevated alkaline phosphatase (ALP), to identify liver damage and to screen for chronic alcohol abuse.

Limitations: In very rare cases gammopathy may cause unreliable results.

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.