CPT 78491Radiology

Myocrd img pet 1std rst/strs

CPT code 78491 covers PET scan imaging of the heart muscle using one radioactive tracer, performed either at rest or during stress testing. This advanced imaging helps doctors see blood flow to the heart and detect coronary artery disease.

Showing rates for

National Average

Base Medicare rate

$68.90

This calculator gives a typical-case estimate using standard Medicare modifier rules. Actual payment depends on payer policies, documentation, code-specific CMS status indicators, and locality. Verify before billing.

RVU breakdown

Work RVU

1.56

PE RVU (NF)

0.52

MP RVU

0.05

Total RVU

2.13

Conversion factor: 32.3465 · Source: CMS MPFS RVU25A · Confidence: High

NCCI bundling edits

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Billing tips

Verify compliance with National Coverage Determination (NCD 220.6) and Local Coverage Determination requirements before scheduling - PET myocardial imaging has specific coverage criteria including prior test requirements
Impact: Non-compliance results in 100% denial ($68.90 loss per claim); most common reason for denial on this code
Document single-tracer protocol clearly in report - 78491 is for ONE tracer at rest OR stress, not both; if rest and stress are performed sequentially with same tracer on same day, bill 78492 instead
Impact: Incorrect code selection between 78491 and 78492 results in undercoding (potential $100+ loss) or overcoding (audit risk)
Bill facility vs non-facility correctly - this code has identical rates ($68.90) but PE RVU settings differ; ensure place of service code matches actual location
Impact: POS code errors trigger post-payment audits and potential recoupment plus interest
Obtain Advance Beneficiary Notice (ABN) when medical necessity is questionable - particularly for screening, repeat studies within 60 days, or off-label indications
Impact: Without valid ABN, cannot collect from patient if Medicare denies; protects practice from $68.90+ write-off
Append modifier 26 for professional-only billing in hospital settings where hospital owns equipment - verify payor split requirements as commercial payors may have different PC/TC breakdowns
Impact: Missing modifier 26 in hospital setting triggers overpayment recovery averaging $30-40 per claim
Link appropriate ICD-10 codes demonstrating medical necessity - primary codes should reflect chest pain (R07.x), CAD history (I25.x), or abnormal cardiac test findings; avoid screening codes

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Frequently asked questions

What is the Medicare reimbursement rate for CPT code 78491 in 2025?

The 2025 Medicare national average reimbursement for CPT 78491 is $68.90 for both facility and non-facility settings. This is based on 2.13 total RVUs (1.56 work RVU, 0.52 PE RVU, 0.05 MP RVU) multiplied by the 2025 conversion factor of 32.3465. Actual reimbursement varies by geographic locality adjustment.

What is the difference between CPT codes 78491 and 78492?

CPT 78491 covers PET myocardial imaging with one tracer administered for either rest OR stress imaging only (single study). CPT 78492 covers multiple studies with the same tracer, typically rest and stress imaging performed sequentially on the same day. Billing 78491 when both rest and stress are performed is incorrect coding and results in underpayment.

Does CPT 78491 require prior authorization from Medicare?

Prior authorization requirements vary by Medicare Administrative Contractor (MAC) and jurisdiction. Many MACs require prior authorization for cardiac PET under NCD 220.6, particularly when medical necessity criteria are not clearly met. Additionally, documentation of prior non-invasive testing or specific clinical scenarios is typically required to meet coverage criteria even without formal prior auth.

Can CPT 78491 be billed with a professional component modifier?

Yes, modifier 26 should be appended when billing only the professional component (physician interpretation). This is common in hospital settings where the facility owns the PET equipment and bills the technical component separately with modifier TC. The professional component represents approximately 40-50% of the total allowable amount.

What diagnosis codes support medical necessity for CPT 78491?

Appropriate ICD-10 codes include chest pain syndromes (R07.89, R07.9), known coronary artery disease (I25.10, I25.110-I25.119), personal history of MI (Z86.74), abnormal cardiac stress test results (R93.1), dyspnea (R06.0), and specific angina codes (I20.x). Screening codes or nonspecific symptoms without cardiac context typically result in denials.

How often can CPT 78491 be billed for the same patient?

Medicare generally limits cardiac PET imaging to once per year unless there is documented clinical change warranting repeat study. Acceptable reasons for repeat imaging include new onset symptoms, post-revascularization evaluation, conflicting prior test results, or significant change in clinical status. More frequent studies require strong medical necessity documentation and may require ABN.

What are the National Coverage Determination requirements for billing 78491?

NCD 220.6 covers cardiac PET for evaluating myocardial viability prior to revascularization or following inconclusive SPECT study in specific clinical scenarios. Coverage requires documented prior non-invasive cardiac testing (with limited exceptions), specific clinical indications such as chest pain with intermediate pre-test probability, and appropriate use criteria compliance. Studies not meeting NCD criteria will be denied as not reasonable and necessary.