Summary & Overview
CPT 0540U: AlloSure dd‑cfDNA Test for Transplant Rejection Monitoring
CPT code 0540U designates the proprietary AlloSure® dd–cfDNA test from CareDx® Laboratory, a next‑generation sequencing (NGS) molecular assay used for transplant monitoring to estimate the probability of organ rejection. As a PLA code, 0540U is specific to a single manufacturer's test and is used when measuring donor‑derived cell‑free DNA in plasma to quantify the proportion of graft‑derived DNA in the recipient’s bloodstream. The code matters nationally because molecular assays for graft surveillance are increasingly integrated into post‑transplant care pathways and payer coverage discussions, with implications for clinical decision making and lab billing consistency.
Key payers examined include Aetna, Blue Cross Blue Shield plans, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the code’s clinical purpose, the typical service setting, and the role of NGS dd‑cfDNA testing in detecting potential rejection. The publication summarizes benchmarking and coverage considerations, highlights relevant policy and coding context for proprietary laboratory analyses, and provides practical information for billing and claims preparation where available. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 0540U is a Proprietary Laboratory Analyses (PLA) code that applies exclusively to the AlloSure® test offered by CareDx® Laboratory. The test measures donor–derived cell–free DNA (dd–cfDNA) levels in plasma to help determine the probability of organ rejection by calculating the percentage of DNA in the recipient’s bloodstream that originates from the transplanted organ using next–generation sequencing (NGS).
Service Type: Laboratory test—molecular diagnostics for transplant monitoring
Typical Site of Service: Clinical laboratory or outpatient blood draw collection site, with analysis performed by the manufacturer’s laboratory.
Clinical & Coding Specifications
Clinical Context
A 52-year-old patient with a history of kidney transplantation presents for routine post-transplant surveillance. The transplant nephrologist orders AlloSure® to measure donor-derived cell-free DNA (dd-cfDNA) from a peripheral blood draw to assess the probability of active allograft injury or rejection. A phlebotomy technician obtains a plasma specimen in the outpatient infusion clinic or laboratory. The specimen is sent to CareDx® Laboratory using validated collection and shipping procedures. CareDx® performs next-generation sequencing (NGS) analysis to quantify the percentage of dd-cfDNA. The laboratory report returns a dd-cfDNA percentage and interpretive guidance indicating whether levels are consistent with low probability of rejection or suggestive of potential rejection, prompting correlation with clinical assessment, serum creatinine, urinalysis, and possible indication for biopsy.
Typical site of service: outpatient hospital laboratory, independent reference laboratory, or outpatient transplant clinic. Service type: Proprietary Laboratory Analyses (PLA) — specialized molecular diagnostic assay for transplant monitoring.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | Default professional and technical components included | Use when reporting the single PLA test service without additional modifier indicating altered service |