CPT code 0039U designates a Proprietary Laboratory Analyses (PLA) assay: the University of Washington’s anti–dsDNA high salt/avidity test, which identifies salt‑resistant antibodies to double‑stranded DNA and has predictive value for systemic lupus erythematosus (SLE) disease activity. As a PLA code, 0039U represents a single manufacturer‑ or laboratory‑specific diagnostic and is used to uniquely identify that test for billing and tracking.

Key payers in scope for national coverage and reimbursement considerations include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find context on the clinical purpose of the assay, the service and site of service where it is typically performed, and what inclusion as a PLA code implies for coding precision. The publication also outlines common modifier usage (provided in the input) and indicates where data were not supplied.

This summary serves clinicians, laboratory administrators, and billing professionals seeking a concise reference on CPT code 0039U: what the code represents, why it matters clinically for SLE monitoring, and which major national payers are relevant for coverage discussions. Data not available in the input are noted where applicable; this piece does not provide state‑level specifics or actionable reimbursement advice.