Headline: CPT code 80156 — Lab assay for total carbamazepine level

CPT code 80156 identifies a laboratory test that measures the total serum concentration of carbamazepine, capturing both the bound and free fractions. This assay supports therapeutic drug monitoring for clinicians managing epilepsy and other neurologic or psychiatric conditions treated with carbamazepine. Accurate total-level measurement is important for dosing decisions, toxicity assessment, and documentation of adherence.

Major national payers commonly covering this service include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Coverage policies and prior-authorization requirements vary by payer and clinical context.

This publication explains the clinical purpose of CPT code 80156, typical service settings, and the types of operational and policy considerations readers can expect to find in the full document. Topics include payer coverage and coding considerations, common claim modifiers and technical components, and clinical context for when total carbamazepine testing is ordered. Where specific input data was not provided, the text notes that the information is not available in the input. The content is written for a national audience of coding professionals, laboratory managers, and policy analysts.