CPT 81332 SERPINA1 Genetic Test Reimbursement

CPT code 81332 identifies a molecular diagnostic laboratory test that detects common sequence changes in the SERPINA1 gene, the gene responsible for encoding alpha-1 antitrypsin. This assay is clinically important for diagnosing alpha-1 antitrypsin deficiency and guiding management of patients with unexplained emphysema, liver disease, or a family history suggestive of the disorder. Nationally, accurate coding for genetic testing affects lab reimbursement, utilization tracking, and access to targeted therapies.

Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise explanation of the code’s clinical context and typical site of service, along with an outline of what to expect in payer coverage discussions. The publication summarizes common modifier usage and notes where data is not available in the input, and it highlights the role of this molecular test in diagnostic workflows.

The report is intended to inform billing professionals, laboratory managers, and policy analysts about the clinical purpose of CPT code 81332, common operational settings for the test, and the payers commonly involved in coverage decisions. Data not available in the input will be explicitly flagged elsewhere in the full publication.

Billing Code Overview

CPT code 81332 describes a laboratory technical test performed to detect common variants in the SERPINA1 gene (serpin peptidase inhibitor, clade A, alpha–1 antiproteinase, antitrypsin, member 1). The procedure represents a molecular diagnostic assay that identifies genetic changes associated with alpha-1 antitrypsin deficiency or related conditions.

Service Type: Molecular diagnostic laboratory testing (technical component)

Typical Site of Service: Clinical laboratory or reference molecular diagnostics laboratory

Data not available in the input for payers, associated taxonomies, ICD-10 diagnoses, related codes, and service line.

Clinical Context

A 45-year-old adult with a history of early-onset panacinar emphysema and a family history of alpha-1 antitrypsin deficiency is referred by a pulmonologist for genetic testing. The provider orders genomic testing to detect common SERPINA1 gene variants associated with alpha-1 antitrypsin deficiency. A phlebotomy appointment is scheduled at an outpatient laboratory; blood is drawn, labeled, and shipped to a molecular diagnostics laboratory. A lab analyst performs the technical assay to detect common pathogenic and deficiency-associated alleles in the SERPINA1 gene, documents assay quality control, analyzes results, and generates a technical report. The ordering clinician receives the report and integrates genotype results into the patient’s diagnostic and management plan, which may include referral to a specialty clinic, cascade testing of family members, or consideration of augmentation therapy if clinically indicated.

Coding Specifications

Modifier	Description	When to Use
`26`	Professional component	Use when billing only the professional interpretation component if the laboratory charges separately for professional services and the professional component is distinct from the technical test.
`TC`	Technical component

Taxonomy Code	Specialty	Notes
363L00000X	Clinical Laboratory Geneticist / Molecular Diagnostics	Physicians or PhDs directing molecular diagnostic laboratories that perform SERPINA1 testing.
207RC0000X	Pulmonology	Ordering specialists who commonly request alpha-1 antitrypsin genetic testing.
208000000X	Family Medicine	Primary care clinicians who may order testing for patients with family history or early COPD.
207Q00000X	Medical Genetics	Providers involved in genetic counseling and interpretation of SERPINA1 results.
207K00000X	Internal Medicine	Internists who manage chronic lung disease and coordinate genetic testing.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`E88.01`	Alpha-1-antitrypsin deficiency	Primary diagnosis linked directly to SERPINA1 genetic testing to confirm or characterize deficiency.
`J43.9`	Emphysema, unspecified	Genetic testing may be ordered for patients with early-onset or atypical emphysema to evaluate for alpha-1 antitrypsin deficiency.
`J44.9`	Chronic obstructive pulmonary disease, unspecified	COPD patients, especially younger or with family history, are evaluated for alpha-1 antitrypsin deficiency with SERPINA1 testing.
`R91.8`	Other nonspecific abnormal findings of lung field	Incidental radiographic findings that raise suspicion for underlying genetic causes may prompt testing.
`Z15.01`	Genetic susceptibility to malignant neoplasm of lung	While not directly diagnostic for AAT deficiency, genetic susceptibility codes may be used when genetic risk assessment is part of evaluation; included as related context in genetic testing workflows.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`83020`	Alpha-1 antitrypsin assay; quantitative	A protein phenotype or serum level test often ordered alongside genetic testing to assess alpha-1 antitrypsin concentration.
`81479`	Unlisted molecular pathology procedure	Used when a specific molecular assay does not have a dedicated CPT; rarely used if testing falls outside defined codes.
`81162`	CYP2C19 gene analysis, common variants	Example of another targeted pharmacogenomic test performed in the same molecular lab; workflow similarities (sample processing, sequencing/genotyping).
`0000U`	Molecular pathology code (proprietary)	Represents possible proprietary or panel-based codes used by labs for multi-gene panels that include SERPINA1; relates when broader panels are ordered.
`G0452`	Pharmacogenetic testing for medication management (Medicare specific)	Sometimes performed in coordination with genetic testing services in the molecular diagnostics environment.

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Summary & Overview

CPT 81332: SERPINA1 (Alpha-1 Antitrypsin) Genetic Test