CPT code 0054U is a Proprietary Laboratory Analyses (PLA) code for the AssuranceRx Micro Serum assay by Firstox Laboratories, LLC. The test employs chromatography and tandem mass spectrometry (LC–MS/MS) on a capillary blood specimen to detect and quantify prescription medications. As a PLA code, 0054U identifies a single manufacturer-specific diagnostic assay and is used for billing when that specific test is performed.

This code matters nationally because laboratory PLA codes enable payers and providers to track utilization and cost for unique, manufacturer-specific diagnostics that traditional general lab CPT codes do not capture. Key payers analyzed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. These payers have varying policies for coverage of specialized pharmacologic and toxicology testing, which can influence access and reimbursement for assays like AssuranceRx Micro Serum.

Readers will learn the clinical context and service setting for CPT code 0054U, how PLA designations affect billing and tracking, and which national payers are relevant to reimbursement discussions. The publication also covers benchmarks, coding guidance, and policy considerations relevant to proprietary laboratory assays, offering a concise reference for coding, billing, and clinical teams evaluating or ordering this test.