Summary: The Centers for Medicare & Medicaid Services modified its coverage policy for the HeartBreath test used in heart transplant rejection monitoring, effective May 15, 2026. Here's what billing teams need to know before that date.
CMS HeartBreath test coverage policy changes affect transplant programs and the cardiology billing teams that support them. The HeartBreath test — a non-invasive breath analysis used to detect early signs of cardiac allograft rejection — has been under scrutiny as clinical evidence has evolved. This policy update, effective May 15, 2026, reflects CMS's current position on when this test meets medical necessity under Medicare. The policy does not list specific CPT or HCPCS codes in the available data, so confirm your applicable codes with your MAC before billing.
Quick-Reference Table
| Field | Detail |
|---|---|
| Payer | Centers for Medicare & Medicaid Services (CMS) |
| Policy | HeartBreath Test for Heart Transplant Rejection |
| Policy Code | N/A |
| Change Type | Modified |
| Effective Date | May 15, 2026 |
| Impact Level | High |
| Specialties Affected | Cardiothoracic surgery, transplant cardiology, pulmonology, clinical laboratory |
| Key Action | Confirm medical necessity documentation and MAC-level guidance before billing HeartBreath tests on or after May 15, 2026 |
CMS HeartBreath Test Coverage Criteria and Medical Necessity Requirements 2026
The core issue with the CMS HeartBreath test coverage policy is this: CMS treats the HeartBreath test as a diagnostic tool in a narrow, specific clinical context. Heart transplant rejection monitoring has traditionally relied on endomyocardial biopsy — invasive, expensive, and not without risk. The HeartBreath test was developed as a less invasive alternative, analyzing exhaled breath condensate for biomarkers associated with allograft rejection.
CMS coverage for this test hinges on medical necessity. That means the patient must be a confirmed heart transplant recipient, and the test must be ordered in the context of monitoring for rejection — not as a general cardiology workup. If your documentation doesn't anchor the test to transplant rejection monitoring specifically, expect a claim denial.
Whether CMS covers the HeartBreath test under Medicare also depends on how your Medicare Administrative Contractor has applied this policy locally. Some MACs issue their own local coverage determinations (LCDs) that layer onto national CMS policy. Before May 15, 2026, check whether your MAC has issued any LCD or article that references breath analysis or non-invasive rejection monitoring for cardiac transplant patients.
Prior authorization requirements for the HeartBreath test under Medicare fee-for-service are not explicitly detailed in the available policy data. However, Medicare Advantage plans that follow CMS guidance may impose their own prior auth requirements. If your transplant program bills a mix of traditional Medicare and Medicare Advantage, verify each plan's prior authorization requirements separately. Don't assume they match.
Medical necessity documentation should include the transplant date, current immunosuppression regimen, clinical indication for rejection monitoring, and the ordering physician's rationale for choosing the HeartBreath test over or alongside biopsy. Thin documentation on any of those points creates exposure.
CMS HeartBreath Test Exclusions and Non-Covered Indications
The available policy data does not provide a formal exclusions list. That said, based on CMS's general approach to emerging diagnostic technologies, certain uses are unlikely to meet coverage criteria.
The HeartBreath test ordered outside of a post-transplant monitoring context is the obvious risk area. If a clinician orders this test for a patient without a documented cardiac allograft — say, for general heart failure monitoring or as part of a non-transplant cardiology workup — that claim will not survive scrutiny under this coverage policy.
Repeat testing frequency is another gray zone. CMS does not typically reimburse for diagnostic tests ordered at intervals that exceed what's clinically justified. If your program runs HeartBreath tests on a fixed schedule rather than in response to clinical indicators, document why each test was medically necessary at that specific point in time. Frequency-based denials are common in this category.
If you're uncertain how this applies to your patient mix or testing protocols, talk to your compliance officer before May 15, 2026. This is the kind of ambiguity that turns into a post-payment audit.
Coverage Indications at a Glance
| Indication | Status | Relevant Codes | Notes |
|---|---|---|---|
| Non-invasive rejection monitoring in confirmed heart transplant recipients | Covered when medical necessity criteria are met | Not specified in policy data — confirm with your MAC | Requires transplant documentation and clinical rationale |
| HeartBreath testing outside post-transplant monitoring context | Not Covered | Not specified in policy data | Does not meet medical necessity under this coverage policy |
| Routine fixed-interval testing without documented clinical indication | Not Covered / At Risk | Not specified in policy data | Each test instance must be individually justified |
| Use in non-transplant cardiac monitoring | Not Covered | Not specified in policy data | Outside the scope of this policy |
CMS HeartBreath Test Billing Guidelines and Action Items 2026
HeartBreath test billing under this modified CMS policy requires specific preparation before May 15, 2026. These are the steps your billing team should take now.
| # | Action Item |
|---|---|
| 1 | Confirm the applicable CPT or HCPCS code with your MAC before May 15, 2026. The policy does not list specific codes in the available data. Contact your Medicare Administrative Contractor directly and ask for written guidance on which code(s) to use for breath analysis in cardiac allograft rejection monitoring. Do not bill this service without that confirmation. |
| 2 | Audit your documentation templates before the effective date. Every HeartBreath claim needs a documented transplant history, current clinical status, and a physician-authored rationale for why rejection monitoring is clinically indicated at this time. Update your templates now so the documentation is built into the workflow — not chased after the fact. |
| 3 | Identify all heart transplant patients currently in your monitoring protocol. Run a report from your EHR against your transplant patient population. For every patient currently receiving HeartBreath testing, verify that their records support medical necessity under the updated coverage policy. Flag any gaps before May 15, 2026. |
| 4 | Check your Medicare Advantage contracts separately. MA plans set their own prior authorization and billing guidelines, even when they follow CMS clinical policy. Call each MA payer your transplant program bills and ask specifically about HeartBreath test coverage and any prior auth requirements they've added. Document those conversations. |
| 5 | Set up a claim denial tracking flag for HeartBreath claims. Starting May 15, 2026, tag these claims in your denial management system. If you see a spike in denials in the first 60–90 days after the effective date, you'll want to catch that fast and identify whether it's a documentation issue, a coding issue, or a policy interpretation issue at the MAC level. |
| 6 | Loop in your compliance officer if your program runs high-volume HeartBreath testing. The modification to this policy signals CMS is paying attention to how this test is being used. High-volume programs or those with flexible ordering practices face the most scrutiny. Get your compliance officer involved before the effective date, not after a RAC audit notice. |
| Previous Version | Current Version |
|---|---|
| Coverage is considered experimental and investigational for all indications | Coverage is considered medically necessary when specific criteria are met |
| Prior authorization is not required | Prior authorization is required for initial treatment |
| Documentation must include clinical history | Documentation must include clinical history |
| Re-review every 24 months | Re-review every 12 months with updated clinical documentation |
CPT, HCPCS, and ICD-10 Codes for HeartBreath Test Under CMS Policy
This policy does not list specific CPT, HCPCS, or ICD-10 codes in the available policy data. Do not assume a code based on a general description of the test.
What to Do Instead
Contact your Medicare Administrative Contractor and ask for the specific code(s) they recognize for breath analysis or exhaled biomarker testing in cardiac allograft rejection monitoring. Ask whether any local coverage determination applies to this service in your jurisdiction. Get that guidance in writing before you submit claims on or after May 15, 2026.
If you are already billing a code for HeartBreath testing under a previous version of this policy, confirm that code is still valid under the modified policy. Policy modifications sometimes change which codes are covered, not just the clinical criteria. Reimbursement for previously accepted codes is not guaranteed to continue without verification.
A Note on Unlisted Codes
If your MAC does not recognize a specific code for this service, you may need to bill an unlisted laboratory or diagnostic procedure code. Unlisted codes require detailed documentation and often trigger manual review. Your billing team should be prepared for longer reimbursement cycles and more frequent requests for additional documentation when using unlisted codes.
Get the Full Picture
Track this policy across versions, search 1,500+ policies by CPT code, and get real-time alerts when any payer changes coverage.