Summary & Overview
CPT 81383: High-Resolution HLA Class II Allele Technical Test
CPT code 81383 describes the technical component of a high-resolution molecular test for one Class II HLA allele or allele group. High-resolution HLA typing is clinically important for organ and stem cell transplantation, certain immunogenetic evaluations, and precise diagnosis or risk assessment for immune-mediated conditions. The code captures the laboratory work required to generate detailed allele-level HLA results.
Key payers included in this analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a national overview of what CPT code 81383 represents, typical service settings, and the clinical context that drives utilization. The publication highlights benchmarking metrics, payer coverage considerations, and recent policy or coding guidance where available.
This summary is intended for laboratory directors, billing professionals, clinicians involved in transplant or immunogenetics, and policy analysts. It explains the clinical role of high-resolution HLA Class II testing, expected sites of service, and what to expect from payer interactions and documentation requirements. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 81383 describes a technical laboratory test that provides a high-resolution assessment of human leukocyte antigen (HLA) genes for a single Class II allele or allele group. The service is typically performed when detailed HLA typing is needed for clinical correlation with a specific condition, such as transplantation compatibility or certain immune-mediated disorders.
Service Type: High-resolution HLA Class II allele technical testing (laboratory service)
Typical Site of Service: Clinical laboratory or reference molecular diagnostics laboratory
Clinical & Coding Specifications
Clinical Context
A 32-year-old woman being evaluated for kidney transplantation is referred to the HLA laboratory for high-resolution typing of a Class II allele associated with transplant compatibility. The clinical workflow begins with the transplant coordinator ordering HLA testing to identify donor-recipient compatibility and to refine risk of rejection. A blood specimen is collected in the outpatient infusion or phlebotomy area and sent to the molecular diagnostics laboratory. The lab analyst performs 81383 for high-resolution assessment of one Class II allele or allele group (commonly HLA-DRB1 or HLA-DQB1), using sequence-based typing or next-generation sequencing. Results are posted to the electronic medical record and transmitted to the transplant team; results guide crossmatch interpretation, donor selection, and immunologic risk stratification. The typical site of service is an outpatient phlebotomy center, hospital laboratory, or independent clinical molecular laboratory performing specialized immunogenetics testing. Common payors ordering this testing include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, BUCA plans, and Medicare.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | When the physician or qualified professional interprets and signs the test report separate from the technical lab work |
TC | Technical component | When the facility/lab performs the technical testing without a separate professional interpretation |
90 | Reference (outside) laboratory | When 81383 is performed by an outside reference laboratory and billed by the ordering provider |
59 | Distinct procedural service | When 81383 is submitted with another service on the same day that is distinct and unrelated |
62 | Two surgeons | Rarely used; when two qualified professionals share responsibility for interpretation in complex genetic evaluations |
76 | Repeat procedure by same physician | When the identical HLA allele test is repeated by the same provider during the same episode (note: 76 is not in the provided list; not used) |
22 | Increased procedural services | When extraordinary labor or interpretation increases the work beyond typical for high-resolution HLA typing |
52 | Reduced services | When a partial or limited technical process is performed compared with full protocol |
53 | Discontinued procedure | When testing was started but aborted for valid clinical or specimen reasons |
90 | Reference (outside) laboratory | When the testing is performed by a contracted external laboratory (duplicate entry omitted in final billing) |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
| 207Q00000X | Clinical Molecular Biology | Laboratory specialists who perform molecular HLA typing and sequence analysis |
| 207L00000X | Clinical Laboratory | Clinical laboratory directors overseeing testing operations and quality |
| 2080P0004X | Pathology | Pathologists who review and sign immunogenetics and molecular diagnostics reports |
| 208000000X | Laboratory Medicine | Physicians specializing in laboratory medicine responsible for test oversight |
| 207K00000X | Clinical Cytogenetics | Specialists involved when genetic counseling or cytogenetic correlation is needed |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
Z94.0 | Kidney transplant status | HLA typing ordered for donor-recipient compatibility and post-transplant monitoring |
Z94.1 | Heart transplant status | Typing needed to assess donor compatibility and risk stratification |
Z48.21 | Encounter for aftercare following kidney transplant | Used when HLA typing assists in evaluation of graft function or rejection workup |
D47.Z9 | Myeloproliferative disease, unspecified | HLA typing may be requested when planning hematopoietic stem cell transplantation |
Z21 | Asymptomatic human immunodeficiency virus [HIV] infection status | HLA typing can be relevant for research or specific clinical decision-making in transplant contexts |
N18.9 | Chronic kidney disease, unspecified | Pre-transplant evaluation often includes HLA typing to prepare for potential transplantation |
T86.100 | Unspecified complication of kidney transplant | HLA testing may be used during evaluation of suspected rejection or complications |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
81381 | HLA class I (eg, HLA-A, B, C) high-resolution typing for one allele or allele group | Often performed in parallel with 81383 to provide comprehensive donor-recipient HLA matching across Class I loci |
81384 | HLA class II (eg, HLA-DR, DQ, DP) high-resolution typing for additional allele groups | Performed when multiple Class II alleles require high-resolution typing beyond the single allele covered by 81383 |
0022U | HLA antibody identification by single antigen bead assay (reporting code for proprietary tests) | Frequently performed before or after 81383 to characterize recipient anti-HLA antibodies for crossmatch interpretation |
86816 | HLA antibody testing, serum, single antigen bead assay (not an official CPT long-term code here—used as example) | Used with HLA typing to assess sensitization and risk of antibody-mediated rejection |
83520 | Sequence analysis, molecular pathology procedure (example adjunct code) | Technical sequencing methods that may be part of the laboratory workflow supporting high-resolution HLA typing |