Summary & Overview

CPT 83915: 5'-Nucleotidase Enzyme Assay, Serum or Synovial Fluid

CPT code 83915 designates a laboratory assay for 5'-nucleotidase (5 NT), an enzyme measurement most often performed on serum or synovial fluid to evaluate hepatic contribution to elevated enzymes. Although historically useful for distinguishing liver-derived enzyme elevations, the test is ordered less frequently today because clinicians commonly use newer liver enzyme panels.

Key national payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise clinical and billing context for CPT code 83915, including where the test is typically performed, common service settings, and the clinical rationale for ordering the assay. The publication summarizes how the code is classified within laboratory service lines and outlines the common modifiers associated with laboratory billing when available from input data.

This report provides practical benchmarks and policy-oriented information relevant for payer contract teams, laboratory billing managers, and clinicians who must document and code enzymatic liver function tests. It also highlights shifts in clinical utilization that affect coding frequency and payer coverage patterns. Data not available in the input are noted where relevant.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareCPT 83915laboratory5-nucleotidaseliver enzymeenzymatic assayclinical pathologyserum testingsynovial fluid

Billing Code Overview

CPT code 83915 reports a laboratory assay measuring 5'-nucleotidase (5 NT) enzyme activity, typically performed on serum or synovial fluid. The test assesses 5'-nucleotidase activity that is predominantly derived from the liver, and it has historically been used as a marker of hepatic origin for certain enzyme elevations. Clinicians now order this assay less frequently because newer liver enzyme tests are more commonly used.

Service type: Laboratory diagnostic test (enzymatic assay)

Typical site of service: Clinical laboratory or hospital laboratory (outpatient or inpatient blood/synovial fluid testing)

Clinical & Coding Specifications

Clinical Context

A 58-year-old male presents to the outpatient laboratory after referral from his primary care physician for evaluation of abnormal liver function tests. He reports mild right upper quadrant discomfort and a history of chronic alcohol use. Initial hepatic panel shows elevated alkaline phosphatase with relatively normal aminotransferases. The clinician orders an enzymatic assay for 5'-nucleotidase to help determine whether the cholestatic pattern is of hepatic origin rather than bone or other sources.

Specimen collection is typically a serum sample drawn by phlebotomy in the outpatient clinic or hospital laboratory. The specimen is transported to the clinical chemistry lab where the laboratory analyst runs the 83915 assay, documents the result in the laboratory information system, and releases the report to the ordering clinician. Results are reviewed in the context of other liver tests (e.g., alkaline phosphatase, gamma-glutamyl transferase) and clinical findings to support diagnosis of hepatic vs. nonhepatic causes of elevated alkaline phosphatase.

Coding Specifications

Modifier	Description	When to Use
`26`	Professional component	Use when billing only the physician interpretation/professional component for a lab test if applicable.
`TC`	Technical component	Use when billing only the laboratory technical component (equipment, reagents, personnel).
`90`	Reference (outside) laboratory	Use when the test was performed by an outside independent laboratory and results are being billed by the ordering/facility provider.
`91`	Repeat clinical diagnostic laboratory test	Data not available in the input.
`52`	Reduced services	Use if the test was partially performed or limited relative to the full procedure.
`53`	Discontinued procedure	Use if specimen collection or testing was started but discontinued for patient safety or specimen issues.
`59`	Distinct procedural service	Data not available in the input.
`22`	Unusual procedural services	Use when work required to perform or document the test substantially exceeds usual requirements.
`90`	Reference (outside) laboratory	Use when an outside lab performed the test and billing reflects referral (listed above).
`90`	Reference (outside) laboratory	Use as appropriate per payer policy.

Taxonomy Code	Specialty	Notes
2080P0206X	Clinical In Vitro Diagnostics Laboratory	Clinical chemistry laboratories performing enzymatic assays.
2085R0201X	Pathology	Pathologists oversee clinical chemistry and test interpretation.
207RC0000X	Family Medicine	Ordering providers in primary care who request hepatic diagnostic testing.
207L00000X	Internal Medicine	Hospitalist or outpatient internists ordering liver enzyme panels.
213E00000X	Gastroenterology	Specialists ordering targeted hepatic diagnostic testing.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`K83.1`	Cholangitis	Elevated hepatic-derived 5'-nucleotidase can support hepatic cholestasis etiologies.
`K74.60`	Unspecified cirrhosis of liver	Used when chronic liver disease causes cholestatic enzyme elevations.
`K70.30`	Alcoholic cirrhosis of liver without ascites	Alcohol-related liver disease may prompt hepatic enzyme workup including `83915`.
`R74.0`	Nonspecific elevation of levels of transaminase and lactic dehydrogenase	Initial abnormal liver tests leading to further enzymatic differentiation.
`R74.8`	Abnormal serum enzyme levels	Broad category for abnormal hepatic enzymes prompting specific assays like 5'-nucleotidase.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`80076`	Hepatic function panel; blood, includes bilirubin, proteins, and enzymes	Often ordered concurrently to assess broad hepatic function along with `83915` to localize source of alkaline phosphatase elevation.
`84450`	Alanine aminotransferase (ALT)	Commonly performed as part of initial liver enzyme evaluation alongside `83915`.
`82565`	Creatine kinase (CK), total	Data not available in the input.
`82542`	Bilirubin; total	Frequently included in liver testing panels with `83915` to evaluate cholestasis or hepatocellular injury.
`82550`	Bile acids; quantitative	Sometimes ordered when cholestatic disease is suspected in conjunction with `83915`.