Currentblue cross blue shield - tennesseePolicy N/A

Gamma-glutamyl Transferase (GGT) testing — Coverage Criteria

Defines coverage criteria, limitations, and clinical context for serum GGT testing in adults (≥18 years), including indications that meet coverage and when testing is not covered.

Policy Summary

Payerblue cross blue shield - tennessee

PolicyGamma-glutamyl Transferase (GGT) testing — Coverage Criteria

Policy CodePolicy N/A

Change TypeNo material change

Effective DateJul 1, 2023

Next Review DateN/A

Key ActionDocument a clinical indication such as elevated alkaline phosphatase before ordering GGT.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

1maximum reimbursed GGT tests per adult per week

Adults ≥18policy applicability age

Elevated ALPexplicit covered indication

Wellnessexplicitly not covered indication

multipleguideline sources referenced

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Recommended clinical indications

Recommended clinical indications — Serum GGT testing MEETS COVERAGE CRITERIA when ANY of the following are present:

Serum GGT testing (See Note 1) MEETS COVERAGE CRITERIA in individuals with elevated alkaline phosphatase activity.

Serum GGT testing (See Note 1) to assess liver injury, function, and/or disease MEETS COVERAGE CRITERIA when at least one of the following is present: chronic alcohol or drug ingestion; long-term drug therapy known to have a potential for causing liver toxicity; exposure to hepatotoxins; viral hepatitis, amoebiasis, tuberculosis, psittacosis, or similar infections that may cause hepatic injury; primary or secondary malignant neoplasms; diabetes mellitus; malnutrition; disorders of iron and mineral metabolism; sarcoidosis; amyloidosis; lupus; hypertension; gastrointestinal disease; pancreatic disease; or as part of liver function assessment subsequent to liver transplantation.

Specific Indications Where GGT Is Covered

inv-32: Evaluation of elevated alkaline phosphatase; assessment of liver injury/function when associated with listed clinical conditions (see coverage criteria nodes).

Evaluation of elevated alkaline phosphatase: Use GGT to evaluate elevated alkaline phosphatase activity and assess liver injury/function when associated with listed clinical conditions (see Covered Indications).

Supports documentation of indication for testing.

inv-33: Confirmation of hepatic origin for isolated alkaline phosphatase elevation; inclusion in initial liver blood test panel when evaluating for liver disease.

Confirmation of hepatic origin for isolated ALP elevation: When alkaline phosphatase (ALP) is elevated in isolation (normal AST, ALT, bilirubin), confirm hepatic origin with GGT or ALP fractionation prior to further imaging; if GGT is elevated, obtain liver ultrasound.isolated ALP elevation

ACG: strong recommendation, very low evidence; BSG: include GGT in initial investigation panel.

Inclusion in initial liver blood test panel: Include GGT among initial liver blood tests (with bilirubin, albumin, ALT, ALP, and FBC) when evaluating for potential liver disease as recommended by BSG.initial workup

BSG guidance; perform as part of initial investigation.

inv-34: Risk stratification for hepatocellular carcinoma in patients with prior hepatitis C who achieved sustained virologic response.

Risk stratification for HCC after HCV SVR: Consider baseline GGT measurement for risk stratification of hepatocellular carcinoma in patients with prior hepatitis C who have achieved sustained virologic response, as baseline GGT levels correlated with HCC development in a cited cohort.

Study: 642 patients; GGT correlated with HCC development.

inv-35: Evaluation/screening for pediatric NAFLD, general liver disease workup, and identification of heavy alcohol use.

Pediatric NAFLD and follow-up: Include GGT in evaluation and at each clinic follow-up for pediatric nonalcoholic fatty liver disease (NAFLD) per ESPGHAN/BSPGHAN guidance.

ESPGHAN recommends considering GGT in screening labs; BSPGHAN recommends GGT as first-line assessment and at follow-up.

Identification of heavy alcohol use: Measure GGT (with ALT) as a complementary test to identify recent heavy alcohol use or risk for alcohol withdrawal per ASAM guidance; GGT alone is insufficient for diagnosis.elevated GGT

ASAM recommends GGT for detecting recent heavy alcohol consumption.

General liver disease workup: Use GGT as part of a broader liver disease workup when indicated by clinical context and other abnormal liver chemistries.

Guidelines note low sensitivity/specificity; interpret alongside other tests.

inv-36: Second-line biochemical testing after abnormal liver screening tests (ALT, AST, ALP).

Second-line biochemical testing: Use GGT as a second-line biochemical test when at least one initial liver screening test (ALT, AST, or ALP) is abnormal; GGT may be included among follow-up labs or performed as part of initial testing if follow-up is impractical.abnormal ALT, AST, or ALP

CAG guidance; can be performed if returning for follow-up is inconvenient.

inv-37: Evaluation of abnormal liver chemistries, assessment of cholestasis, and prognostic evaluation in liver and metabolic disease as supported by cited guidelines and studies.

Evaluation of abnormal liver chemistries: Employ GGT to assist in evaluation of abnormal liver chemistries and assessment of cholestasis, and consider its prognostic role in liver and metabolic disease in the context of cited guidelines and studies.

References include ACG, EASL, and multiple studies linking GGT with liver disease, metabolic syndrome, cardiovascular outcomes, and other conditions.

Provider Actions, Documentation and Authorization

Documentation Required

Documentation and Coverage Requirements

Claims for GGT testing as part of a wellness check or general encounters without abnormal findings will not meet coverage criteria. Document a covered clinical indication (e.g., elevated alkaline phosphatase or one of the listed causes such as chronic alcohol/drug ingestion, hepatotoxin exposure, viral hepatitis, long‑term hepatotoxic drug therapy, malignancy, diabetes, malnutrition, iron/mineral disorders, sarcoidosis, amyloidosis, lupus, hypertension, gastrointestinal or pancreatic disease, or post‑liver transplant assessment). A maximum of one unit of GGT per week will be reimbursed for adults; repeat testing after a normal GGT is generally not necessary unless new indications are present per NCD 190.32.

Wellness/General Encounter Denial: GGT testing ordered solely as part of a routine wellness visit or without abnormal liver chemistries will be denied.
Required Clinical Indication: Document the specific clinical reason for testing (e.g., isolated elevated ALP to confirm hepatic origin, signs of liver injury, chronic alcohol use, hepatotoxic exposure, viral hepatitis, post‑transplant evaluation).
Claim Payment Limit: Reimbursement is limited to one unit of GGT per week for adults.

Note

Government Policy Supersedes

If there is any conflict between this policy and an applicable government policy (e.g., Medicare LCDs or NCDs, or state Medicaid coverage), the government policy supersedes and will be used to make determinations. Providers must follow the most current Medicare and state Medicaid guidance where applicable.

Government policy supersedes this policy when conflicts exist (e.g., LCDs, NCDs).
Check CMS Medicare Coverage Database and applicable state Medicaid sites for updates.

Note

Policy Adoption and Effective Date

This policy adopts the Avalon policy recommendation effective 7/1/2023. Reimbursement and utilization review will follow the adopted Avalon criteria; failure to meet the Avalon/adopted policy requirements may result in claim denial or non‑payment.

Effective date: 2023-07-01 — Avalon policy recommendation adopted.
Providers should follow any prior authorization or utilization review requirements that derive from the adopted Avalon policy.

Step Therapy

Guideline‑Driven Provider Actions Prior to Evaluation

Before initiating evaluation of abnormal liver chemistries, repeat the liver chemistry panel and/or perform a clarifying test (e.g., GGT when ALP is elevated) to confirm the abnormality. When ALP is elevated in isolation, confirm hepatic origin with GGT or ALP fractionation prior to imaging or further workup. If ALP elevation occurs with other abnormal liver chemistries (AST/ALT/bilirubin), confirmation with GGT is not required.

Guideline‑driven step: For isolated ALP elevation, obtain GGT (or ALP fractionation) to confirm hepatic origin before ordering imaging or hepatology referral.
Repeat testing: Repeat liver chemistry panel or perform clarifying tests to confirm initial abnormal results prior to additional evaluation.
When ALP is elevated along with other abnormal liver tests, proceed with evaluation without requiring GGT confirmation.

Billing Rule

Specimen and Laboratory Considerations

Serum biomarkers including GGT should preferably be obtained in fasting patients when recommended by the guideline or test manufacturer, and laboratories should follow manufacturer instructions and validation procedures for assays. Clinical literature supports the use of GGT as a complementary test but notes limited specificity — document how results will affect patient management.

Obtain serum biomarkers (including GGT) preferably in fasting state when indicated by the test or guideline.
Laboratory‑developed tests (LDTs) for GGT are regulated under CLIA as high‑complexity tests; labs must validate in‑house assays per CLIA requirements.
Document clinical justification for ordering GGT and how the result will change management given GGT's limited specificity.

Ordering Requirements and Restrictions

Documentation Required

Orders must be supported by documented clinical indication

Order should be supported by a documented clinical indication such as elevated ALP or one of the listed clinical conditions; the policy is intended for adult individuals (≥18 years).

Note

No provider-type ordering restrictions stated

The excerpt does not place ordering restrictions by provider type; include GGT in initial evaluation panels typically ordered by clinicians evaluating abnormal liver tests or suspected liver disease per cited guidelines.

Billing Rule

GGT may be ordered with panels after abnormal screening or as initial panel

GGT can be ordered as part of liver biochemical panels following abnormal liver screening tests or as part of an initial panel when it is inconvenient for the patient to return for follow-up; ensure order aligns with guideline recommendations.

Documentation Required

Order consistent with cited clinical guidelines

Orders for GGT should be consistent with the clinical guidelines cited (e.g., clinicians evaluating abnormal liver tests or suspected cholestasis should follow guideline-recommended testing sequences and documentation).

Frequency Limits and Testing Interval Guidance

inv-38: GGT (serum) — 1

TestGGT (serum)

Frequency limitMaximum reimbursed: 1 unit per week for adult individuals

Applicable populationAdults ≥18 years

inv-39: No explicit frequency limits provided in this excerpt.

Explicit frequency limitsNo additional explicit frequency limits provided in this excerpt beyond the 1 unit/week reimbursement note

Studies referencedSome studies report serial GGT variability assessments over multiple years, but do not set policy frequency limits

NoteClinical repeat testing guidance referenced in NCD 190.32 recommends against routine repeat after normal result unless new indications arise

inv-40: GGT at each clinic follow-up for pediatric NAFLD.

RecommendationAssess GGT at each clinic follow-up for pediatric NAFLD

ContextBSPGHAN recommends GGT as part of first-line liver function assessment in pediatric NAFLD

Associated testsIncludes ALT, AST, ALP, split bilirubin, FBC, coagulation screen, albumin, fasting lipid profile, and others per BSPGHAN guidance

inv-41: GGT — general frequency placeholder.

General frequency guidancePolicy states maximum reimbursement of one GGT unit per week for adults; routine repeats after a normal result generally not necessary unless new indications present (per NCD 190.32)

ExceptionsPediatric NAFLD guidance recommends GGT at each clinic follow-up (see BSPGHAN guidance) — not a general adult frequency rule

DocumentationRepeat testing should be clinically justified and documented (e.g., new signs/symptoms or change in treatment)

Tests and Indications Not Covered

Serum GGT testing performed as part of wellness checks or general encounters without abnormal findings is specifically listed as not covered and will not meet coverage criteria.

Routine population screening for liver disease using GGT alone is not supported by the cited guidelines and therefore is not indicated or covered. Guideline statements emphasize confirming abnormal liver chemistries before relying on GGT for further evaluation.

NASPGHAN and ESPGHAN guidance do not recommend routine measurement of GGTP for evaluation of cholestatic jaundice in young infants; NASPGHAN (2004) explicitly states GGTP is "not routinely recommended" in this setting because variability limits interpretation and it is not part of the official recommendation set.

No additional tests or clinical indications are explicitly identified as not covered in this section beyond those already described.

Definitions and Test Names

inv-28: GGT / GGTP — definition and use summary.

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

PhysiologyCell membrane enzyme present in multiple tissues including liver, bile duct, kidney, heart, brain, spleen, and gallbladder

Clinical useMeasured in serum to assess liver dysfunction, biliary disease, and alcohol-related liver injury; emerging research links GGT to metabolic and cardiovascular conditions

inv-29: GGT (gammaglutamyl transferase / gamma-glutamyl transpeptidase) — definition.

Full nameGGT (gammaglutamyl transferase / gamma-glutamyl transpeptidase)

DefinitionAn enzyme measured in serum used to evaluate liver function, particularly for confirmation of cholestasis and as an adjunct marker for alcohol-related liver injury

Guideline noteACG recommends GGT to confirm hepatic origin when ALP is elevated but cautions against using GGT alone as a population screening test due to low specificity

inv-30: GGTP / GGT — alternate name definition.

Alternate nameGGTP (gamma-glutamyl transpeptidase), also referred to as GGT

Historical useUsed historically to help distinguish causes of cholestasis, though variability limits interpretation in some pediatric contexts

LimitationsNASPGHAN notes GGTP/GGT is not routinely recommended for cholestasis evaluation in young infants due to wide variability

inv-31: GGT — additional definition and context.

Clinical roleGGT is a serum enzyme measured to assess liver function, cholestasis, and as a potential prognostic biomarker in metabolic and cardiovascular disease

ResearchMultiple studies and reviews link GGT with diabetes risk, cardiovascular disease, stroke, and other outcomes (see cited literature)

PopulationPolicy applies to adult individuals aged 18 years and older

OpenPayer

Gamma-glutamyl Transferase (GGT) testing — Coverage Criteria

Coverage Criteria for Serum GGT Testing

Specific Indications Where GGT Is Covered

Covered / Affected Codes

Provider Actions, Documentation and Authorization

Ordering Requirements and Restrictions

Frequency Limits and Testing Interval Guidance

Tests and Indications Not Covered

Background and Clinical Context

Definitions and Test Names

Guidelines and Evidence Cited

Policy Revision History