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 |
22 | Increased procedural services | Use when test requires substantially greater resources or complexity beyond usual — documented justification required |
52 | Reduced services | Use when the assay is partially performed with documentation of reduced scope or incomplete testing |
53 | Discontinued procedure | Use when specimen collection or testing was begun but discontinued for documented clinical or technical reasons |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
207RP0000X | Transplant Hepatologist | Clinicians who manage liver transplant recipients and order dd-cfDNA when clinically indicated |
2080P0208X | Nephrology | Transplant nephrologists commonly order AlloSure® for kidney allograft surveillance |
207L00000X | Clinical Laboratory | Clinical laboratory directors and molecular diagnostics specialists perform or oversee NGS testing |
2084N0402X | Pathology | Molecular pathology specialists interpret complex NGS-based transplant monitoring assays |
208D00000X | Internal Medicine | General internists in transplant programs may order and coordinate surveillance testing |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
T86.10 | Unspecified complication of kidney transplant | Indicates possible graft dysfunction where dd-cfDNA monitoring assists in evaluating rejection probability |
T86.12 | Chronic rejection of kidney transplant | Used when monitoring is performed in the context of suspected or known chronic rejection |
Z94.0 | Kidney transplant status | Surveillance testing in stable transplant recipients to monitor for subclinical injury |
N18.9 | Chronic kidney disease, unspecified | Underlying kidney disease context; dd-cfDNA used to distinguish graft injury from other causes of dysfunction |
R94.5 | Abnormal results of liver function studies | Example of abnormal laboratory finding prompting dd-cfDNA in non-kidney solid organ transplant contexts (if applicable) |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
0540U | AlloSure® dd-cfDNA, quantitative NGS assay performed by CareDx® Laboratory (Proprietary Laboratory Analyses) | Primary PLA code used to report the AlloSure® assay for transplant rejection surveillance |
36415 | Collection of venous blood by venipuncture | Often performed immediately prior to sending plasma specimen for dd-cfDNA testing |
36416 | Collection of capillary blood specimen | Alternate collection method in select outpatient settings if validated by laboratory |
81002 | Urinalysis, non-automated, without microscopy | Common adjunctive test in transplant surveillance alongside dd-cfDNA to evaluate graft function |
82043 | Microalbumin; quantitative (e.g., urine) | May be performed concurrently as part of kidney transplant monitoring |