ModifiedBlue Cross Blue Shield - OklahomaPolicy CPCPLAB056

Gamma-glutamyl Transferase (GGT) testing

Laboratory reimbursement and management criteria for serum gamma-glutamyl transferase (GGT) testing for BCBSOK products; governs billing and medical necessity expectations for providers submitting claims to Blue Cross Blue Shield of Oklahoma.

Policy Summary

PayerBlue Cross Blue Shield - Oklahoma

PolicyGamma-glutamyl Transferase (GGT) testing

Policy CodePolicy CPCPLAB056

Change TypeReimbursement and frequency updatesremoved indication

Effective DateNov 1, 2023

Next Review DateN/A

Key ActionFollow the revised reimbursement guidance: do not bill for serum GGT for asymptomatic wellness/general exam patients and apply the new frequency limits (no more than once every two weeks) for covered indications.

SourceLink

POLICY UPDATE CHANGES

Document updated with literature review and revisions to reimbursement information, including removal of drug ingestion from 2a and addition of frequency to #1 and #2 from Note 1.

Frequency was added to items #1 and #2 (previously referenced in Note 1).

Drug ingestion was removed from item 2a in Reimbursement Information.

Literature references were revised/updated.

>=18minimum age referenced

2 wksmax frequency

wellnessnot reimbursable

Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.

Coverage Criteria for Serum GGT Testing

Reimbursable indications and frequency

Covered when ALL of the following are met

Adult elevated ALP pathway: For individuals 18 years of age or older with elevated alkaline phosphatase activity, serum GGT testing no more than once every two weeks may be reimbursable.age >= 18; frequency <= every 2 weeks

Reimbursement item 1

Assessment of liver injury/function/disease

Listed conditions (one or more): a. Chronic alcohol use; b. Long-term drug therapy known to have a potential for causing liver toxicity; c. Exposure to hepatotoxins; d. Viral hepatitis, amoebiasis, tuberculosis, psittacosis, or similar infections that may cause hepatic injury; e. Primary or secondary malignant neoplasms; f. Diabetes mellitus; g. Malnutrition; h. Disorders of iron and mineral metabolism; i. Sarcoidosis; j. Amyloidosis; k. Lupus; l. Hypertension; m. Gastrointestinal disease; n. Pancreatic disease; o. As part of liver function assessment subsequent to liver transplantation.

Serum GGT testing for asymptomatic individuals during a wellness visit or a general exam without abnormal findings is not reimbursable. This exclusion applies to routine screening in individuals who have no signs or symptoms suggesting liver disease or abnormal laboratory findings at the time of the visit.

Note: drug ingestion was removed from reimbursement item 2a in the Reimbursement Information during the 7/17/2023 update; as a result, testing for drug ingestion is no longer listed as an allowed/reimbursable indication under that item.

Serum GGT testing performed for asymptomatic individuals during a wellness visit or a general exam without abnormal findings is considered not reimbursable. Providers should expect denial when billing for GGT as routine screening in asymptomatic members absent qualifying clinical indications.

Covered Indications and Clinical Scenarios

Elevated alkaline phosphatase in individuals 3E=18 years

Covered when ALL of the following are met

Elevated alkaline phosphatase — adults: Individual is 18 years of age or older AND has elevated alkaline phosphatase activity.age >= 18

Testing frequency limit: Serum GGT testing for this indication is limited to no more than once every two weeks.frequency <= every 2 weeks

Assessment of liver injury/function/disease in individuals 3E=18 years with at least one listed clinical condition

Covered when ALL of the following are met

Coding, Age, and Frequency

Procedure Codesmixed

No codes listed

Age

Minimum age for reimbursable testing>= 18 years

Age group referencedAdults 18 years of age or older

Applies toAll covered reimbursable indications in policy (elevated ALP pathway and listed clinical conditions)

Maximum testing interval

Maximum testing intervalNo more than once every two weeks

Frequency applies toSerum GGT testing for covered indications (elevated ALP and listed clinical conditions)

Period definition

Frequency Limits for Testing

Serum GGT — Frequency limit

Test nameSerum GGT (gamma-glutamyl transferase)

Frequency limitNo more than once every two weeks

Context of useApplied when testing for elevated alkaline phosphatase or assessment of liver injury/function in adults

Serum GGT — Frequency addition to reimbursement items

Policy changeFrequency was added into numbered items #1 and #2 (previously referenced in Note 1)

Exact frequencies in updateDocument notes frequency added to items #1 and #2, but exact frequency text is represented in item language (no additional separate numeric values elsewhere)

Provider Actions, Documentation, and Billing Notes

Billing Rule

Provider Actions and Billing Notes

Reimbursement Information was revised. Providers should follow the updated reimbursement information and frequency specifications. Note 1 was removed and certain indications (for example, drug ingestion from prior item 2a) were removed which may affect reimbursement.

Reimbursement Information revised: frequency limits added to items 1 and 2 (GGT testing no more than once every two weeks for specified indications).
Providers should follow the updated reimbursement information and frequency specifications; Note 1 removed.
Providers are responsible for submission of accurate documentation and may be asked to submit additional documentation to support medical necessity.
Serum GGT testing for asymptomatic individuals during a wellness/general exam without abnormal findings is not reimbursable and may be denied.
Removal of certain indications (e.g., drug ingestion from prior 2a) may affect reimbursement and could trigger prior authorization or claim denials.

Ordering and Authorization Requirements

Note

Ordering clinician types not specified; documentation required

The policy does not specify particular clinician types who may order testing; providers remain responsible for accurate documentation and appropriate coding when ordering and billing serum GGT.

Ensure orders are supported by clinical documentation that meets the reimbursable indications and frequency limits.
Code claims according to HIPAA-approved code sets and industry standards.

Note

No ordering-role specification in these sections

Ordering requirements (who may order serum GGT) are not specified in the cited policy sections.

Not Covered / Exclusions

Screening GGT testing for asymptomatic individuals during a wellness visit or a general exam without abnormal findings is not covered. This policy excludes routine GGT screening in the absence of clinical indications or abnormal findings.

Drug ingestion (previously listed in item 2a) was removed from the Reimbursement Information and is no longer a covered indication. This policy revision (7/17/2023) explicitly removed that indication from the reimbursable list.

Definitions and Clinical Terms

Definition of reimbursable adult scenarios

Definition (adult scenario)An adult (>=18 years) with elevated alkaline phosphatase activity

Alternative reimbursable adult scenarioAn adult (>=18 years) with at least one listed clinical condition (e.g., chronic alcohol use; long-term hepatotoxic drug therapy; exposure to hepatotoxins; viral hepatitis; malignant neoplasms; diabetes; malnutrition; disorders of iron/mineral metabolism; sarcoidosis; amyloidosis; lupus; hypertension; gastrointestinal disease; pancreatic disease; or post-liver transplant assessment)

Age requirementMust be 18 years of age or older

GGT — Definition and clinical associations

DefinitionGamma-glutamyl transferase (GGT) is a serum enzyme associated with liver function and oxidative stress

Clinical associations (literature)

Background

Gamma‑glutamyl transferase (GGT) is a serum enzyme used in the assessment of liver injury, liver function, and liver disease. GGT levels can be elevated with various hepatic and systemic conditions; the policy describes circumstances where serum GGT testing may be reimbursable (for example, elevated alkaline phosphatase or listed clinical conditions) and clarifies exclusions and frequency limits added in the 2023 update.