Summary & Overview
CPT 81319: PMS2 Large Deletion/Duplication Analysis
CPT code 81319 identifies the technical laboratory service for detecting large deletions or duplications in the PMS2 gene, a mismatch-repair gene relevant to hereditary cancer risk. Nationally, molecular diagnostics for mismatch-repair genes are a key component of hereditary cancer evaluation, impacting diagnostic pathways, surveillance decisions, and family cascade testing. The code represents the technical execution of assays that assess copy-number changes across long DNA sequences in PMS2.
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 clinical context for PMS2 copy-number testing, the typical laboratory setting and service type, and an outline of payer considerations. The publication summarizes available benchmarks and coverage patterns where present, highlights relevant policy and coding updates that affect reimbursement and claims adjudication, and clarifies coding scope and use in the laboratory workflow. The intent is to give clinicians, laboratory administrators, and billing professionals a clear national-level overview of what CPT code 81319 represents and the operational and policy topics most likely to affect its use.
Billing Code Overview
CPT code 81319 describes a laboratory molecular genetic test that detects large deletions or duplications in the PMS2 gene (postmeiotic segregation increased 2 [S. cerevisiae]).
Service Type: Genetic testing — technical laboratory component
Typical Site of Service: Clinical laboratory or reference molecular diagnostics laboratory
This code applies to the technical performance of assays designed to identify long-sequence copy-number changes (deletions/duplications) in the PMS2 gene, which is evaluated in contexts where hereditary cancer syndromes and mismatch repair gene defects are suspected. Data not available in the input.
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult or adolescent referred for germline genetic testing because of personal or family history suggestive of Lynch syndrome or other hereditary colorectal and endometrial cancer syndromes. The clinician (genetic counselor, gastroenterologist, oncologist, or primary care physician) orders molecular testing targeting the PMS2 gene to detect large deletions or duplications that are not identified by sequence analysis alone. A blood or saliva specimen is collected in the outpatient phlebotomy lab or a specialty genetics clinic. The specimen is accessioned and routed to a molecular diagnostics laboratory where a lab technologist performs the technical assay described by CPT 81319 (analysis for long-sequence deletions/duplications in PMS2).
Pre-analytic steps include verifying patient identity, appropriate consent for genetic testing, and insurance authorization. The technical procedure typically uses multiplex ligation-dependent probe amplification (MLPA), long-range PCR, or targeted copy-number analysis by next-generation sequencing with bioinformatic calling and confirmation as needed. The lab produces a technical report and, when applicable, sends results to the ordering provider who may incorporate a professional interpretation by a board-certified molecular geneticist (reporting the variant classification and recommendations for cascade testing). Typical sites of service are outpatient hospital laboratories, independent clinical genetic testing laboratories, or hospital-based molecular pathology labs. Indications include unexplained early-onset colorectal cancer, multiple Lynch-related cancers in a patient or family, abnormal tumor testing (e.g., loss of PMS2 protein expression on immunohistochemistry), or a known familial PMS2 copy-number variant requiring targeted testing.