CPT code 82977: GGT test2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Measures blood gamma-glutamyltransferase to evaluate liver or biliary disorders and help assess the source of an elevated alkaline phosphatase.
Medicare pays $7.20 for 82977 under the 2026 Clinical Laboratory Fee Schedule: one national amount, the same in every state and setting.
Medicare lab fee · CLFS 2026 Q4
National CLFS amount
$7.20
In effect since Jan 1, 2026. The same amount in every state, payment locality and setting.
- Geographic adjustment
- None
- Office vs facility
- Same
- Since 2020
- Unchanged
- QW · CLIA-waived test
- $7.20
Medicare pays the lesser of the lab’s charge and this amount. Patients usually owe no Part B deductible or coinsurance for covered clinical lab tests.
On this page 8 sections
What 82977 covers
Gamma-glutamyltransferase (GGT) is a liver-associated enzyme measured in a blood specimen, typically serum. Clinicians order the assay when evaluating suspected liver or biliary disease, including cholestatic patterns, or to help determine whether an elevated alkaline phosphatase is hepatobiliary in origin. GGT may also be considered in evaluating alcohol-related liver injury, but the result is interpreted with the clinical picture and other liver tests. Clinical laboratories perform and report the assay for physician practices, hospitals, and other ordering settings.
Report one assay for each GGT test performed. A CLIA-waived version is reported with modifier QW; sites holding a CLIA certificate of waiver may perform it. Medicare pays this test through the CLFS at one national amount per code, with no locality or office-versus-facility difference. The 2026 national CLFS amount is $7.20, unchanged since 2020. The test is paid only through the CLFS, not the physician fee schedule.
This summary was written with AI assistance from CMS Clinical Laboratory Fee Schedule data. Amounts on this page come directly from CMS files.
How Medicare pays 82977
Clinical lab tests aren’t priced like physician services. They’re paid from their own fee schedule, with its own rules. See the whole lab fee schedule.
One national amount
CMS sets a single Clinical Laboratory Fee Schedule amount for 82977. There’s no geographic (GPCI) adjustment, so it pays the same in every state and payment locality.
No office or facility rate
Lab tests aren’t built from relative value units, so there’s no office and facility split: the place of service doesn’t change the CLFS amount.
Updated every quarter
CMS republishes the CLFS each quarter. New tests, often proprietary laboratory analyses (PLA codes), join during the year; existing amounts are updated each January.
Excluded from the physician fee schedule
The physician fee schedule lists 82977 with status X (excluded by statute), so the test itself is paid only from the CLFS.
CLIA-waived version (QW)
CMS also lists 82977 with modifier QW, the version labs holding a CLIA certificate of waiver bill. It pays $7.20.
82977 on the lab fee schedule since 2020
82977 · CLFS 2026 Q4 (current)
$7.20
Unchanged since Jan 1, 2020
27 quarterly CLFS releases on file, first CLFS 2020 Q1. A code missing from a quarter wasn’t on that release.
82977 compared with similar tests
- 84075Alkaline phosphatase$5.18
- 84075 measures alkaline phosphatase, a different enzyme. GGT may be paired with it to help assess whether an elevated alkaline phosphatase is hepatobiliary in origin.
- 80076Liver panelSeven liver chemistry tests$8.17
- 80076 reports a hepatic function panel. GGT is not a standard panel component and is reported separately when performed.
- 82978Glutathione assayGlutathione protein level$15.45
- 82978 measures glutathione, not gamma-glutamyltransferase. The similar names do not indicate the same analyte or test.
82977 billing questions
How is GGT different from alkaline phosphatase?
GGT measures a different enzyme. Clinicians may use it alongside alkaline phosphatase to help assess whether an elevated alkaline phosphatase has a hepatobiliary source.
Should GGT be reported as part of a hepatic function panel?
GGT is a separate assay, not a standard component of the hepatic function panel. Report it separately when it is performed.
When should modifier QW be used?
Use QW for the CLIA-waived version when the testing site holds a CLIA certificate of waiver.
How many units should be reported?
Report one unit for each GGT assay performed; do not use additional units to represent the measured enzyme level.
How does Medicare pay for this test?
Medicare pays it under the CLFS at one national amount per code. The amount is the same across localities and does not vary between office and facility settings.
Where this amount comes from
FeeBase reads lab amounts directly from the CMS Clinical Laboratory Fee Schedule file for the quarter: one row per code, with its payment indicator and national amount. Contractor-priced tests are labeled, never given a made-up amount. Amounts are Medicare payment limits, not a patient’s bill or a commercial rate.
CMS CLFS 2026 Q4 · effective Oct 1, 2026 through the day before Jan 1, 2027
Show the CMS file line behind this amount
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