CurrentCapital BluecrossPolicy AHS - G2173

Gamma-glutamyl Transferase Testing in Adults

Clinical coverage criteria and background for serum GGT testing for adults (age ≥18) including indications, frequency limits, and situations where testing is not covered; intended for Capital Bluecross providers and reviewers.

Policy Summary

PayerCapital Bluecross

PolicyGamma-glutamyl Transferase Testing in Adults

Policy CodePolicy AHS - G2173

Change TypeNo material change noted

Effective Date05/26/2020

Next Review DateMar 1, 2026

Key ActionOrder serum GGT only when a covered indication is documented and limit testing to no more than once every two weeks.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

≥18age group this policy applies to

1/2 wksmax covered frequency

Not coveredwellness exam stance

1CPT code listed

65+evidence refs cited

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Coverage Criteria for Serum GGT Testing

Medically Necessary Uses

Covered when ALL of the following are met:

ALL of the following

Patient is 18 years of age or older.
Serum GGT testing is being ordered to evaluate an abnormal liver screening test (e.g., elevated ALT, AST, or ALP) or to clarify an abnormality in the liver chemistries.
ANY of the following
- Elevated alkaline phosphatase activity where GGT is used to help determine hepatic vs bone source of ALP elevation (GGT testing up to once every two weeks).
  Part of initial workup when ALP is isolated or to confirm hepatic origin.
- - Chronic alcohol use.
  - Long-term drug therapy known to have potential for hepatotoxicity.
  - Exposure to hepatotoxins.
  - Viral hepatitis, amoebiasis, tuberculosis, psittacosis, or similar infections that may cause hepatic injury.
  - Primary or secondary malignant neoplasms of the digestive system.
  - Diabetes mellitus.
  - Malnutrition.
  - Disorders of iron and mineral metabolism.
  - Sarcoidosis.
  - Amyloidosis.
  - Lupus.
  - Hypertension.
  - Gastrointestinal disease.
  - Pancreatic disease.
  - Assessment of liver function subsequent to liver transplantation.
- Use as part of serum biomarker panels or noninvasive indices to assess hepatic fibrosis risk or prognostication (e.g., GGT-to-platelet ratio, GPR) or to aid risk stratification for hepatocellular carcinoma after HCV eradication.
- Assessment of recent heavy alcohol use or alcohol-related liver disease in conjunction with other markers (e.g., ALT, carbohydrate-deficient transferrin) or when monitoring alcohol-related liver disease.

Specific Indications Where GGT is Covered

Confirmation of hepatic origin of isolated alkaline phosphatase elevation

Confirmation of hepatic origin of isolated alkaline phosphatase elevation and inclusion in the initial liver workup when at least one liver screening test is abnormal.

Isolated ALP elevation: Isolated elevated alkaline phosphatase with normal other liver screening tests (ALT, AST, bilirubin).isolated ALP elevation

ACG recommends confirmatory testing with GGT (chunk 27); CAG lists GGT among initial biochemical tests when any screening test is abnormal (chunk 31).

GGT as confirmatory test: Measure serum GGT to determine hepatic origin of ALP elevation.

Per ACG guidance in chunk 27.

Follow-up imaging: If GGT is elevated, obtain liver ultrasound for further evaluation.

Situations Where GGT Testing Is Not Covered

Denial Risk

Situations Where GGT Testing Is Not Covered

Requests for serum GGT testing for asymptomatic individuals during a wellness visit or general exam without abnormal findings will be denied.

Prior Authorization: Not required specifically for GGT when denial rule applies — see payer-specific authorization policies for lab panels.
Conflict with government policy: Medicare/Medicaid specifications may differ; apply applicable state and federal regulations when determining coverage.

Testing Frequency Limits

inv-33: serum GGT — No more than once every two weeks

TestSerum GGT (gamma-glutamyl transferase)

Frequency limitNo more than once every two weeks

Applies toAdults (≥18 years)

Covered indication exampleEvaluation of elevated alkaline phosphatase activity

inv-34: (placeholder key_value from inventory — empty summary captured for writer fallback)

SummaryNo summary available in the inventory for this item.

Action

Ordering, Documentation, and Operational Requirements

Prior Authorization

Document indication and adhere to frequency limit (adults only)

Ordering clinician must document that the patient is an adult (≥18 years), the specific covered clinical indication is present, and that testing frequency does not exceed once every two weeks; coverage depends on member benefits and meeting these criteria.

Note

When to order GGT — isolated ALP or abnormal liver screen

Order GGT to confirm the hepatic origin of an isolated alkaline phosphatase (ALP) elevation or include GGT as part of the initial liver biochemical panel when at least one liver screening test (ALT, AST, or ALP) is abnormal.

Note

Ordering-provider restrictions

No specific ordering-provider restrictions are specified in the policy; the guidance applies to the ordering clinician documenting the indication and frequency for adults.

Provider Actions, Billing, and Denial Risks

Prior Authorization

Prior authorization guidance

No explicit prior authorization requirement is stated in the policy; coverage is contingent on member benefits and meeting the listed indications and frequency limits.

Billing Rule

Coding and laboratory validation (CPT 82977; LDTs under CLIA)

Bill GGT testing using CPT code 82977 (Glutamyltransferase, gamma [GGT]); laboratories may perform laboratory‑developed tests (LDTs) which must be validated and are regulated under CLIA as high-complexity tests.

Prior Authorization

Prior authorization and code reference (82977)

There is no specific prior authorization statement tied to CPT codes in the policy; when submitting claims include CPT 82977 as the procedure code for GGT.

Procedure Codes and Coding Guidance

Covered CPT CodesCPTCovered

82977

Glutamyltransferase, gamma (GGT)

Applicable CPT/HCPCS Procedure CodesCPTCovered

82977

Glutamyltransferase, gamma (GGT)

inv-10: None listed — placeholder key_value for coding details

Thresholds listedNone listed

Coding section referenceSee Applicable CPT/HCPCS Procedure Codes for code listing

NoteProcedure codes in policy are provided as a general reference and may not be all-inclusive.

Background and Clinical Context

Gamma-glutamyl transferase (GGT) is a cell-membrane enzyme abundant in the liver and present in multiple other tissues. It is used clinically to help assess liver dysfunction, cholestasis, and patterns related to alcohol use. GGT may be elevated in many hepatic and extrahepatic conditions and can aid in determining whether an alkaline phosphatase elevation is hepatic in origin; however, it has limited specificity for liver disease.

inv-24: GGT / GGTP — definition and brief notes

TermGGT / GGTP (gamma-glutamyl transferase / gamma-glutamyl transpeptidase)

DefinitionAn enzyme present in the cell membrane of many tissues (liver, kidney, heart, brain, bile duct, spleen, etc.) used as a marker for liver dysfunction, cholestasis, and alcohol consumption; half-life 14–26 days.

Clinical noteMay be elevated in numerous hepatic and extrahepatic conditions and is not specific for liver disease.

inv-25: Gamma-glutamyl transferase (GGT) — recommended to confirm hepatic origin of an isolated alkaline phosphatase elevation and complementary test

Definitions and Terminology

inv-24: GGT / GGTP definition entry

TermGGT / GGTP

DefinitionGamma-glutamyl transferase (GGT), also known as gamma-glutamyl transpeptidase (GGTP), an enzyme present in cell membranes of multiple tissues used as a marker for liver dysfunction, cholestasis, and alcohol consumption; half-life 14–26 days.

Clinical implicationElevation is not specific for liver disease and may occur with cardiac, renal, pancreatic disease and certain medications.

inv-26: GGT (CPT code) definition entry for coding cross-reference

CPT82977

DescriptionGlutamyltransferase, gamma (GGT)

Evidence-based Scientific References

The policy cites multiple guideline and observational references to support recommendations and limitations for GGT testing. See the Evidence-based Scientific References for society guidelines (ACG, EASL, CAG, ASAM, BSG) and primary studies that inform coverage decisions.

Policy Revision History

2026-03-01policy_reviewLatest

Policy last reviewed; clinical coverage criteria for serum GGT reconfirmed with no material changes to clinical statements.

Policy Summary

PayerCapital Bluecross

PolicyGamma-glutamyl Transferase Testing in Adults

Policy CodePolicy AHS - G2173

Change TypeNo material change noted

Effective Date05/26/2020

Next Review DateMar 1, 2026

Key ActionOrder serum GGT only when a covered indication is documented and limit testing to no more than once every two weeks.

SourceLink

On This Page

Planner notes and policy recommend ultrasound when hepatic source is confirmed (coverage rationale).

Assessment for liver injury, function, and/or disease

Covered up to once every two weeks when at least one listed risk/condition is present.

Indication documentation: Document at least one qualifying condition (e.g., chronic alcohol use; hepatotoxic drug therapy; exposure to hepatotoxins; viral hepatitis; digestive system malignancy; diabetes; malnutrition; iron/mineral metabolism disorders; sarcoidosis; amyloidosis; lupus; hypertension; GI or pancreatic disease; post-liver transplant).at least one listed condition

From policy III.2a–o.

Frequency limit: Serum GGT testing performed no more than once every two weeks.≤1 test per 2 weeks

Policy III.2 frequency restriction.

Assessment of recent heavy alcohol use or alcohol-related liver disease

Used to assess recent heavy alcohol use or alcohol-related liver disease when interpreted with other laboratory markers.

Clinical indication: Chronic alcohol use or clinical suspicion of recent heavy alcohol consumption.

Listed indication in policy III.2a and ASAM guidance (chunk 32).

Adjunct markers: Perform GGT alongside other markers (e.g., ALT, CDT) to improve detection of high-risk alcohol use.

Conigrave et al. and Rosoff et al. support combined marker use (chunk 24).

Frequency limit: Testing no more than once every two weeks when used for alcohol assessment.≤1 test per 2 weeks

Policy frequency restriction (chunk 3).

Use as part of serum biomarker panels to assess hepatic fibrosis risk or prognostication

Incorporation of GGT into composite indices and use for prognostication when clinically indicated.

Composite index use: Include GGT in indices such as GPR (GGT-to-platelet ratio), FIB-4, or APRI to assist in noninvasive assessment of hepatic fibrosis.

Hu et al. and other studies (chunks 22, 37) support improved performance when GGT is incorporated.

Prognostic application: Use GGT for risk stratification, including identifying higher risk for hepatocellular carcinoma after hepatitis C eradication, when supported by clinical context.

Chunk 22 links baseline GGT with HCC development post-HCV eradication.

Frequency limit: Testing no more than once every two weeks when used for risk stratification or prognostication.≤1 test per 2 weeks

Policy frequency restriction (chunk 3).

Various clinical uses supported by cited literature

Additional literature-supported clinical uses; covered when consistent with listed indications and frequency limits.

Supported uses: Evaluation of abnormal liver chemistries; assessment of obstructive jaundice/cholestasis as part of differential testing; monitoring alcohol-related liver disease; inclusion in noninvasive fibrosis assessments and prognostic evaluations.

Supported by guideline and observational references (chunks 27, 32, 37).

Coverage condition: Testing must meet one of the covered indications and adhere to the frequency limit (no more than once every two weeks).≤1 test per 2 weeks

Policy-wide requirement (chunk 3).

Refer to related coverage criteria and frequency limits in the policy for guidance.

NoteThis placeholder entry contains no additional structured data.

Documentation Required

Required clinical indication and frequency documentation

Clinical documentation must support one of the listed covered indications (e.g., elevated alkaline phosphatase; chronic alcohol use; hepatotoxic drug therapy; viral hepatitis; malignancy of the digestive system; diabetes; malnutrition; disorders of iron/mineral metabolism; sarcoidosis; amyloidosis; lupus; hypertension; GI or pancreatic disease; post-liver transplant) and the intended testing frequency (no more than once every two weeks).

Documentation Required

Recommended confirmatory testing and initial panel

Repeat an abnormal liver panel and/or perform a clarifying test (for example, GGT when ALP is elevated); when ALP is isolatedly elevated, confirm hepatic origin with GGT and, if GGT is elevated, obtain liver ultrasound; initial evaluation should include bilirubin, albumin, ALT, ALP and GGT as indicated.

Step Therapy

Repeat or confirmatory testing before evaluation

Before initiating evaluation of abnormal liver chemistries, repeat the liver panel or perform a clarifying test (for example, GGT when ALP is elevated) to confirm that abnormalities are persistent before further workup.

Billing Rule

Billing: use CPT 82977 on claims

Use CPT code 82977 (Glutamyltransferase, gamma [GGT]) on claims; procedure codes in policy are provided as general reference and may not be all-inclusive.

Note

Apply government policy when conflicts exist

If this policy conflicts with applicable government coverage (e.g., LCD/NCD or state Medicaid), the government policy will be used to make determinations for the member.

Denial Risk

Coding-related denial risk (use CPT 82977)

Claims for GGT testing should be billed using CPT 82977; incorrect or absent use of the listed CPT code may trigger claim processing issues or denials.

Note

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(No additional provider-action content specified in source.)

Note

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(No additional provider-action content specified in source.)

TestGamma-glutamyl transferase (GGT)

Recommended useRecommended to confirm hepatic origin of an isolated alkaline phosphatase elevation and as a complementary test in the initial liver workup when at least one liver screening test is abnormal.

Complementary testsUse alongside ALT, AST, ALP, bilirubin and consider liver ultrasound if GGT is elevated with isolated ALP elevation.

inv-26: GGT (CPT code) — CPT 82977 — Glutamyltransferase, gamma (GGT).

CPT code82977

Code descriptionGlutamyltransferase, gamma (GGT)

Billing noteProcedure codes appearing in Medical Policy documents are included only as a general reference and may not be all-inclusive.

Reference noteListed under Applicable CPT/HCPCS Procedure Codes in the policy.