Summary & Overview
CPT 80178: Quantitative Lithium Assay in Clinical Laboratory
CPT code 80178 represents a quantitative laboratory assay to measure lithium concentration in a patient specimen, a critical test for monitoring therapy in patients treated for bipolar and other mood disorders. Nationally, lithium monitoring is a common component of psychiatric pharmacotherapy management because of lithium's narrow therapeutic window and potential for toxicity. This code captures the technical laboratory work required to perform the assay.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The summary provides a national perspective on clinical context, coverage considerations, and operational benchmarks where available.
Readers will learn what CPT code 80178 denotes, the typical clinical and laboratory settings where it is performed, and the purpose of the test in patient management. The publication outlines available benchmarks and payer coverage patterns when present, highlights relevant policy and billing considerations, and situates the code within therapeutic drug monitoring practices. Data not available in the input will be noted as such where applicable.
Billing Code Overview
CPT code 80178 describes a laboratory assay in which a lab analyst performs the technical procedures needed to quantitate the amount of lithium present in a patient specimen. The service type is therapeutic drug monitoring / quantitative drug assay. The typical site of service is a clinical laboratory or hospital laboratory performing blood or serum testing for monitoring lithium levels in patients treated for bipolar and other mood disorders.
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult with a diagnosis of bipolar disorder or other mood disorder receiving lithium therapy. The clinician orders a 80178 serum lithium level to monitor therapeutic and toxic ranges during initiation, dose adjustment, or routine maintenance. The patient presents to an outpatient laboratory or hospital phlebotomy station after instructions regarding timing of the blood draw (commonly a trough level, drawn 12 hours post-dose when applicable). The specimen is logged, processed by the laboratory technologist, and the technical analysis quantifies serum lithium concentration. Results are reported to the ordering clinician for interpretation alongside clinical status, renal function tests, and concomitant medications. Typical site of service: outpatient laboratory, hospital outpatient phlebotomy, or inpatient hospital laboratory when monitoring occurs during admission. Service type: clinical laboratory quantitative drug assay, therapeutic drug monitoring.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the professional (interpretive) component of a split-payment lab service provided by a physician or qualified provider. |
TC |