When the Senate version of the Medicare Access to Radiology Care Act of 2026 (MARCA) was introduced earlier this year, it offered an important Medicare payment pathway for services performed by radiologist assistants (RAs). The legislation would allow payment to a supervising radiologist for qualifying RA services furnished in certain facility settings. We discussed the Senate bill in late May. 

The Senate version of the bill contained a significant omission: its payment provisions did not include physician office settings.

There was reason to expect that the House companion bill, H.R. 9984, would correct that omission. Unfortunately, the text of the House bill released on July 30, 2026 appears to repeat substantially the same facility limitation. That is disappointing, particularly because physician offices are increasingly important sites for outpatient imaging and minimally invasive radiology services.

What the bills cover

The Senate and House bills would define “radiologist assistant services” as services that would be physician services if furnished by a physician, are performed by an ARRT-certified RA under a radiologist’s supervision, are authorized under applicable state law, and are not separately billed or paid to another provider.

The legislation then limits its specific payment methodology to services furnished in a “covered facility setting.” That term includes:

• a hospital or critical access hospital;
• an ambulatory surgical center; and
• other “providers of services” designated by the Secretary of Health and Human Services.

The Senate text expressly describes the payment provision as applying in hospital and ambulatory surgical center settings. The omission of physician office settings is consequential because both generally participate in Medicare as suppliers rather than as statutory “providers of services.” The Secretary’s authority to add other providers of services therefore cannot confidently be read as authority to add physician offices.

Congress could eliminate the uncertainty simply by naming physician office settings in the bill.

Is incident-to billing an adequate substitute?

The American Registry of Radiologic Technologists has explained that physician offices were not included the MARCA legislation because RA services performed there may already be billed “incident to” a radiologist’s professional services.

That proposition is correct in principle. Medicare’s incident-to regulation, 42 CFR 410.26, permits services furnished by auxiliary personnel in a physician's office to be billed as though they were furnished by the physician. The regulation also requires direct supervision and incorporates the applicable direct-supervision definition in 42 CFR 410.32(b)(3)(ii).

But incident-to billing is not a broad or dependable substitute for an express statutory payment pathway.

Most importantly, an incident-to service must be an integral, although incidental, part of the physician’s professional service in the course of diagnosing or treating a particular patient. The radiologist must personally perform the initiating professional service and remain actively involved in the patient’s course of treatment. An RA generally cannot independently initiate a new course of care or address a new problem and then have the service billed under the radiologist’s name and NPI.

That requirement can be especially difficult in radiology. Radiologists commonly furnish discrete procedural or diagnostic services at the request of another treating practitioner. They may not have previously evaluated the patient or established an ongoing treatment plan of the type ordinarily associated with incident-to billing. It is true that interventional radiologists regularly provide minimally invasive services from their physician office settings, through their IR clinics or office-based laboratories. 

But there does not appear to be widespread use of incident-to billing by radiology groups for office-based thoracentesis, paracentesis, lumbar puncture and similar minimally invasive services performed by RAs. The absence of widespread incident-to billing is understandable given the highly specific requirements and resulting compliance risk.

MARCA should provide a clear office pathway

Incident-to billing may be available for some RA services in some physician offices. But incident-to billing does not independently recognize RAs as Medicare practitioners, and it does not permit payment merely because an RA performed a useful, medically necessary service under a radiologist’s supervision.

The Senate sponsors have described MARCA as improving access in both hospital and office settings and have stated that CMS’s 2019 supervision change allowed reimbursement for RA services in offices. That description overstates what the 2019 Medicare supervision rule change accomplished. The 2019 change did not establish a comprehensive payment pathway for office-based RA services. It permits Level 3 fluoroscopic-guided tests performed by licensed RAs and radiology practitioner assistants (RPAs) to be supersized under direct and not personal supervision.  In other words, if a barium enema is performed by a state-licensed or authorized RA, the radiologist need not perform “in the room” personal supervision. Although the 2019 Medicare rule change permits “direct” supervision of tests like barium studies, it did nothing to expand the role of RAs in performing minimally-invasive radiology procedures.

MARCA remains worthwhile legislation. But Congress should expressly include physician offices in its scope rather than assume that incident-to billing adequately addresses office-based RA services. A statute intended to remove barriers to RA utilization should create a clear, uniform and defensible payment pathway in every appropriate setting where radiologists and RAs provide care.