Summary & Overview
CPT 0087U: Molecular Microscope MMDx—Heart mRNA Transplant Assay
CPT code 0087U identifies a Proprietary Laboratory Analyses (PLA) test — the Molecular Microscope® MMDx—Heart assay from Kashi Clinical Laboratories — that measures mRNA levels in heart transplant biopsy tissue and compares results to a reference library to identify causes of graft dysfunction. This PLA code matters nationally because it denotes a single-manufacturer, high-complexity molecular diagnostic service used in transplant management and can affect coverage, coding consistency, and lab reimbursement decisions across insurers.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise explanation of the clinical purpose and lab setting for the assay, a summary of which payers are included in the review, and an outline of the topics typically addressed in payer and policy assessments for PLA tests. These topics include payer coverage patterns, billing and coding practice considerations for proprietary molecular tests, and clinical context for transplant surveillance and diagnostic differentiation.
The publication presents benchmarks and policy-relevant items for national audiences, highlights payer-specific coverage themes where available, and provides clinical context to inform coding and billing workflows related to proprietary transplant diagnostic assays. Data not available in the input will be noted where applicable.
Billing Code Overview
CPT code 0087U is a Proprietary Laboratory Analyses (PLA) code for the Molecular Microscope® MMDx—Heart test provided by Kashi Clinical Laboratories. The test measures mRNA expression levels in transplanted heart biopsy tissue and compares results to a reference library to determine the likely reason for transplant organ dysfunction or failure.
Service Type: Laboratory molecular diagnostic test (proprietary gene-expression assay)
Typical Site of Service: Clinical laboratory or reference laboratory processing transplant biopsy specimens
Clinical & Coding Specifications
Clinical Context
A 56-year-old patient with a history of orthotopic heart transplantation presents with progressive graft dysfunction identified by rising filling pressures on catheterization, new or worsening heart failure symptoms, or unexplained decline in left ventricular function on echocardiography. Endomyocardial biopsy is performed via right internal jugular venous access in the cardiac catheterization lab or hybrid procedure suite. Fresh-frozen or appropriately preserved biopsy tissue is sent to Kashi Clinical Laboratories for the Molecular Microscope® MMDx—Heart assay, reported with PLA code 0087U. The test measures mRNA expression in the biopsy specimen and compares it to a reference library to help distinguish causes of graft dysfunction such as acute cellular rejection, antibody-mediated rejection, or nonimmune injury. Typical workflow steps: obtain biopsy samples during the catheterization procedure, place specimens in the laboratory-specified transport medium, complete accompanying requisition with clinical history and ICD-10 diagnoses, ship specimens under validated conditions to the performing laboratory, and receive a molecular diagnostic report that informs the transplant team’s differential diagnosis and management planning.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | Unspecified modifier | Rarely used; only if a payer requires a placeholder and no other modifier applies. |
11 | Primary procedure | When 0087U is the principal test billed for the encounter.
26 | Professional component | If reporting only the professional interpretation portion separate from the laboratory technical component (rare for PLA codes).
52 | Reduced services | When the laboratory performs a partial or limited version of the test (e.g., insufficient tissue precludes full analysis).
53 | Discontinued procedure | If the specimen collection was attempted but the procedure was terminated before adequate sampling for testing.
78 | Unplanned return to operating/procedure room | Not typical but used if biopsy required immediate reintervention under the same anesthesia episode.
80 | Assistant surgeon | Not commonly applicable to lab test but relevant to the biopsy procedure when an assistant surgeon is billed.
AD | Medical supervision by a doctor certificate of medical necessity | When Medicare or other payers require physician oversight documentation for complex testing processes.
QK | Medical direction of two to four technicians/technologists | If the performing laboratory documents medical direction consistent with CPT definitions and payer policy.
QX | Rendering clinician is a CRNA working with QZ waiver | Rare for this test; applies if a CRNA is billing components of the procedure under applicable payer rules.
| Taxonomy Code | Specialty | Notes |
|---|---|---|
208000000X | Cardiology | Cardiologists order and interpret transplant monitoring tests and perform endomyocardial biopsy. |
207L00000X | Cardiothoracic Surgery | Cardiac surgeons involved in transplant care and perioperative biopsy or reintervention.
207R00000X | Pathology | Surgical pathologists oversee tissue handling and correlate molecular results with histopathology.
362M00000X | Clinical Laboratory | Laboratory medicine specialists and molecular pathologists run and validate the PLA assay.
283Q00000X | Transplant Surgery | Transplant surgeons coordinate graft surveillance and integrate molecular diagnostics into patient management.
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
T86.21 | Heart transplant rejection | Direct indication for molecular testing to evaluate cause of graft dysfunction. |
I50.9 | Heart failure, unspecified | Presents as clinical manifestation of graft dysfunction prompting biopsy and molecular analysis.
I97.610 | Complications of heart transplant, acute rejection | Used when acute post-transplant rejection is suspected and tissue-based molecular testing is indicated.
I42.9 | Cardiomyopathy, unspecified | Worsening graft function resembling cardiomyopathy may trigger endomyocardial biopsy and 0087U testing.
R94.31 | Abnormal results of other heart-function studies | Abnormal imaging or biomarkers leading to biopsy and molecular diagnostic evaluation.
Z94.1 | Heart transplant status | History code used in surveillance encounters where molecular monitoring is performed.
T86.29 | Other transplant rejection and graft-versus-host disease of heart | Alternative rejection coding when specifics differ from T86.21 and molecular testing aids differential diagnosis.
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
0300U | AlloMap Heart (molecular expression profiling of peripheral blood for heart transplant rejection) | Alternative noninvasive molecular monitoring test used in surveillance; may be ordered instead of or alongside tissue-based testing. |
88305 | Level IV surgical pathology, gross and microscopic examination | Performed when histologic evaluation of endomyocardial biopsy is done; correlates with molecular MMDx results.
36515 | Collection of blood specimen from central venous catheter (non-vascular implantation) | May be billed when central access is used for peri-procedural management; not specific to the test but part of the procedure workflow.
93505 | Endomyocardial biopsy, with or without catheterization; initial biopsy | Billed for the biopsy procedure that provides tissue for 0087U testing.
99000 | Handling and/or conveyance of specimen for transfer from physician's office to a laboratory (may be payer-specific) | Used for specimen handling/shipping logistics when required by payer policies.