CPT code 78491: Myocardial PET, single study2026 Medicare rate & RVUs in California

CMS doesn’t publish an office rate for 78491 in California.

Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.

What 78491 covers

This code represents PET imaging of myocardial perfusion during one study, performed either at rest or under stress. Nuclear medicine and cardiac imaging teams acquire the images after administering a radiopharmaceutical tracer. Clinicians use myocardial perfusion imaging to assess blood flow to the heart muscle, including when evaluating suspected or known coronary artery disease. The study may be performed in a hospital or an imaging practice equipped for cardiac PET.

Medicare assigns status C, meaning there is no national physician fee schedule payment and the Medicare Administrative Contractor prices the claim. The service has professional and technical components: modifier 26 identifies interpretation, modifier TC identifies the equipment and staff portion, and no modifier represents the global service. The code represents a single study, not separate rest and stress studies.

This summary was written with AI assistance from CMS physician fee schedule data and checked against the CMS billing rules shown here. Rates on this page come directly from CMS files.

Where 78491 pays more and less in California

The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.

29 of 29 payment localities

How the 78491 rate is calculated

Each of 78491’s three RVUs is multiplied by a geographic index (GPCI) for the payment locality, added up, and multiplied by the conversion factor. Drag the indexes or enter a ZIP to see what moves the rate.

Payment rules and modifiers for 78491

The CMS indicators that decide how 78491 is paid alongside other services.

What modifiers do to the payment

When to use modifier 26

78491 compared with similar codes

How to choose

78492PET perfusionMultiple studies

78491 represents one PET perfusion study at rest or stress; 78492 represents PET perfusion studies at both rest and stress.

78431Cardiac PETRest and stress with CT

78431 covers PET perfusion at rest and stress with a concurrently acquired CT scan. 78491 is for a single study at rest or stress.

78451Cardiac SPECTSingle rest or stress study

78451 is a single-study myocardial perfusion code using SPECT. Use 78491 when the imaging method is PET.

78452Nuclear stress testSPECT, multiple perfusion studies

78452 describes multiple-study SPECT myocardial perfusion imaging. 78491 describes one PET myocardial perfusion study.

Codes related to 78491

Related codes aren’t interchangeable: bill the code that matches the service performed.

Where these rates come from

FeeBase calculates base physician payments from CMS work, practice-expense and malpractice RVUs, adjusted by each locality’s geographic indexes and the conversion factor. Services without a published rate are labeled, never given a made-up amount. Amounts are Medicare allowed amounts before claim adjustments: not a patient’s bill or a commercial rate.

CMS RVU26D · effective Oct 1, 2026 through the day before Jan 1, 2027

Open CMS sourceHow we calculate rates