Summary & Overview
CPT 0381U: Branched–Chain Amino Acids, SelfCollect Blood Spot
CPT code 0381U designates a Proprietary Laboratory Analyses (PLA) test for Branched–Chain Amino Acids, SelfCollect, Blood Spot, performed by the Mayo Clinic. The assay quantifies allo‑isoleucine, leucine, isoleucine, and valine via liquid chromatography with tandem mass spectrometry (LC–MS/MS) on a patient‑collected blood spot. As a PLA code, 0381U is specific to a single manufacturer or laboratory and signals unique clinical and billing considerations for rare metabolic testing and remote specimen collection.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the test’s clinical purpose and service delivery model, a summary of payer coverage context, and what to expect in benchmarking and policy considerations when a PLA code is in use. The publication highlights implications for remote specimen collection workflows, laboratory processing using LC–MS/MS, and how proprietary single‑source codes affect coding clarity and payer communication.
This national summary is intended to inform billing, laboratory, and payer policy stakeholders about the code’s clinical remit, common administrative considerations, and where to look for coverage and reimbursement guidance for single‑source laboratory assays.
Billing Code Overview
CPT code 0381U is a Proprietary Laboratory Analyses (PLA) code that applies to a single, specific laboratory test: Branched–Chain Amino Acids, SelfCollect, Blood Spot, from Mayo Clinic. The test measures levels of allo–isoleucine, leucine, isoleucine, and valine using liquid chromatography with tandem mass spectrometry (LC–MS/MS) on a patient‑collected blood spot specimen.
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Service type: Clinical laboratory testing of patient‑collected blood spot specimens using LC–MS/MS
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Typical site of service: Home collection by the patient with laboratory analysis performed at the Mayo Clinic laboratory facility
Clinical & Coding Specifications
Clinical Context
A pediatric or adult patient with known or suspected branched-chain amino acid metabolism disorder (for example, suspected or monitored maple syrup urine disease [MSUD] or elevated branched-chain amino acids from metabolic disturbances) receives a home collection kit from Mayo Clinic for a patient‑collected dried blood spot. The patient or caregiver obtains a capillary blood spot per kit instructions and returns the specimen to Mayo Clinic Laboratory. The laboratory performs quantitative measurement of allo‑isoleucine, leucine, isoleucine, and valine using liquid chromatography with tandem mass spectrometry (LC‑MS/MS). Results are reported to the ordering clinician to assist with diagnosis, therapeutic monitoring (dietary or metabolic therapy), or newborn/metabolic follow‑up. Typical site of service is a patient’s home for specimen collection and an independent or reference clinical laboratory (Mayo Clinic) for testing and reporting. The service type is a Proprietary Laboratory Analysis (PLA) for a single‑manufacturer test, billed using 0381U.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the professional component of the test interpretation if separated from technical component billing. |