Summary & Overview
CPT 84078: Alkaline Phosphatase (ALP) After Heat Treatment
CPT code 84078 identifies a laboratory assay that measures alkaline phosphatase (ALP) activity in a specimen following a defined heat treatment. This heat-inactivation step helps separate ALP isoenzymes and refine diagnostic interpretation for hepatobiliary and bone disorders. The code is relevant to clinical laboratories, hospital labs, and clinicians managing abnormal liver-function markers, and it matters nationally because enzymatic isoform differentiation can influence downstream diagnostic pathways and utilization of additional imaging or specialist referral.
Key payers in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will gain a concise overview of the clinical purpose of CPT code 84078, where the service is typically performed, and what to expect in payer coverage contexts. The publication summarizes common billing modifiers and payer considerations (where available), clarifies service-line placement for lab claims, and provides context for how this specialized ALP heat-inactivation test fits into laboratory diagnostic workflows. Data not available in the input is noted when applicable.
Billing Code Overview
CPT code 84078 describes a laboratory procedure in which a lab analyst measures alkaline phosphatase (ALP) activity in a patient specimen after a specific heat treatment. The test evaluates heat-stable versus heat-labile fractions of ALP to help distinguish isoenzyme sources and clinical causes of abnormal ALP levels.
Service Type: Clinical laboratory test — enzymatic assay with heat inactivation step
Typical Site of Service: Clinical laboratory or hospital laboratory
Clinical & Coding Specifications
Clinical Context
A 55-year-old outpatient with a history of suspected cholestatic liver disease presents to the clinic after abnormal liver chemistry results. The clinician orders a heat-stable alkaline phosphatase isoenzyme test to help differentiate bone versus liver sources of elevated alkaline phosphatase. A phlebotomist collects a serum specimen and sends it to the clinical laboratory. The lab analyst performs 84078, which measures alkaline phosphatase activity following a defined heat inactivation procedure to detect heat-stable (often bone) versus heat-labile (often liver) isoenzymes. Results are reported to the ordering provider and integrated into the patient’s hepatology or primary care clinical workflow to guide further testing (for example, imaging or bone turnover studies) or referral.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the professional interpretation or reporting portion if separated from the technical lab processing. |
TC | Technical component | Use when billing only the technical component (laboratory performance of the test) without professional interpretation. |