CPT 81377 HLA Class II Reimbursement & Policy | OpenPayer

Summary & Overview

CPT 81377: HLA Class II Allele Group Typing, Low/Intermediate Resolution

CPT code 81377 designates a laboratory technical procedure for low- or intermediate-resolution assessment of human leukocyte antigen (HLA) genes for one Class II antigen equivalent (allele group). This assay supports clinical decisions in transplantation compatibility, immune-mediated disease evaluation, and certain pharmacogenomic contexts, making it a clinically significant molecular diagnostic billed under laboratory services nationally. Coverage and payment for HLA typing affect hospital and outpatient laboratories, transplant programs, and clinical genetic services.

Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of coverage considerations and common billing practices across major national payers, plus context on clinical utility and service settings. The report outlines typical service lines, sites of service, and the technical nature of the assay. It also summarizes common modifiers observed in billing (input provided) and notes when specific payer policy or coding guidance is not available.

This publication helps laboratory administrators, billing professionals, and clinical program leaders understand what CPT code 81377 represents, how it is used in practice, and where to look for payer-specific policy details. Data not available in the input is identified where applicable; the focus remains on national-level clinical and billing context rather than state-specific rules.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareCPT 81377HLA typingmolecular diagnosticslaboratory servicesclass II antigengenetic testingtransplant compatibilitylab billingmedical coding

Billing Code Overview

CPT code 81377 describes a laboratory technical procedure for low- or intermediate-resolution assessment of human leukocyte antigen (HLA) genes for one Class II antigen equivalent (an allele group of interest). The service is a molecular/genetic laboratory test performed by a laboratory analyst to identify HLA Class II allele groups that may be associated with specific conditions.

Service type: Laboratory — molecular/genetic testing (HLA typing)

Typical site of service: Clinical laboratory or specialized molecular diagnostics laboratory (ambulatory or hospital-based lab setting)

Clinical & Coding Specifications

Clinical Context

A 32-year-old patient with a history of recurrent pregnancy loss is evaluated by a maternal-fetal medicine specialist. The clinician orders human leukocyte antigen (HLA) low- or intermediate-resolution typing for one Class II antigen equivalent to assess allele group compatibility associated with immune-mediated reproductive issues. A phlebotomy technician collects a blood specimen at an outpatient laboratory. The specimen is accessioned and processed in the molecular immunogenetics lab. The lab analyst performs 81377 to determine the allele group for the specified Class II locus (for example, an HLA-DRB1 allele group) using validated low- or intermediate-resolution molecular methods. Results are reported to the ordering clinician, who integrates the HLA allele group information with clinical data for counseling and management decisions such as donor selection or risk assessment. Typical site of service: outpatient hospital laboratory or independent clinical molecular laboratory. Service type: molecular immunogenetics laboratory technical analysis for targeted Class II HLA allele group testing.

Coding Specifications

Modifier	Description	When to Use
`26`	Professional component	Use when billing only the professional (interpretation) component if separated from the technical lab work.

CPT 81375: HLA Class II Low/Intermediate-Resolution Molecular Typing

CPT-81373-HLA-CLASS-I-LOW-INTERMEDIATE-RESOLUTION

CPT 81373: HLA Class I Low/Intermediate Resolution Molecular Test

CPT-81383-HIGH-RESOLUTION-HLA-CLASS-II-ALLELE-TESTING

CPT 81383: High-Resolution HLA Class II Allele Technical Test

CPT-81381-HLA-HIGH-RESOLUTION-CLASS-I-ALLELE-TESTING

CPT 81381: HLA High-Resolution Test for One Class I Allele

CPT-81374-HLA-CLASS-I-LOW-INTERMEDIATE-RESOLUTION

CPT 81374: HLA Class I Low/Intermediate-Resolution Testing

CPT-81379-HLA-CLASS-I-HIGH-RESOLUTION-TYPING

CPT 81379: High-Resolution HLA Class I Typing

CPT-81370-HLA-CLASS-I-II-LOW-INTERMEDIATE-RESOLUTION-TESTING

CPT 81370: HLA Class I and II Low/Intermediate-Resolution Molecular Typing

CPT-81380-HLA-HIGH-RESOLUTION-CLASS-I-TYPING

CPT 81380: High-Resolution HLA Class I Molecular Typing

CPT-81372-HLA-CLASS-I-LOW-INTERMEDIATE-RESOLUTION-TYPING

CPT 81372: HLA Class I Low/Intermediate-Resolution Molecular Typing

CPT-81376-HLA-CLASS-II-TYPING-LOW-INTERMEDIATE-RESOLUTION-TECHNICAL

CPT 81376: HLA Class II Typing, Low/Intermediate-Resolution Technical

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Taxonomy Code	Specialty	Notes
207RH0000X	Hematopathology	Pathologists who oversee immunogenetics and HLA testing in clinical labs.
207L00000X	Clinical Pathology	Clinical pathologists directing laboratory testing and interpretation.
207K00000X	Molecular Genetic Pathology	Specialists in molecular diagnostics who validate and supervise HLA molecular assays.
208D00000X	Obstetrics & Gynecology	Ordering clinicians for reproductive immunology indications such as recurrent pregnancy loss.
208000000X	Family Medicine	Primary care or reproductive medicine clinicians who may order targeted HLA testing.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`Z31.430`	Encounter for fertility testing; infertility evaluation female	HLA typing may be ordered during fertility workup when immunologic factors are considered in recurrent implantation failure.
`O26.82`	Maternal care for other specified fetal problems; recurrent pregnancy loss	HLA allele group testing can be used in evaluation of immune-mediated causes of recurrent pregnancy loss.
`Z48.01`	Encounter for change or removal of surgical dressings; not directly related	Data not directly applicable to this procedure but included when present in input.
`Z52.2`	Blood donor status	HLA testing can be relevant for donor matching in selected transfusion or transplant contexts.
`D76.1`	Hemophagocytic lymphohistiocytosis	HLA associations may be explored in complex immune dysregulation workups where targeted HLA testing contributes to diagnosis.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`81377`	HLA typing; low or intermediate resolution for one Class II antigen equivalent (allele group)	The primary technical assay performed by the molecular immunogenetics laboratory to determine an HLA Class II allele group.
`81376`	HLA typing; low or intermediate resolution for one Class I antigen equivalent (allele group)	Performed when Class I allele group information is required in addition to Class II; may be ordered concurrently for comprehensive HLA assessment.
`81479`	Unlisted molecular pathology procedure	Used for molecular tests not specifically described by existing CPT codes when additional specialized HLA analyses are required beyond `81377`.
`88360`	Immunohistochemistry or immunocytochemistry, per specimen; initial single antibody stain	Occasionally used when correlated antigen expression studies are performed on tissue in conjunction with HLA testing in complex cases.
`80500`	Tissue typing; serologic testing, HLA-A, -B, -C, -DR, -DQ (each antigen) — historical/alternative methods	Historical or alternate methodology codes that may appear in legacy workflows where serologic typing complements molecular HLA results.

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