Medicare Proposes 30 Percent Cut to Proton Therapy Reimbursement Rates
If finalized, the rate reduction would make proton therapy financially unviable at many freestanding centers, concentrating access at larger hospital systems and away from patients in rural or...
The Centers for Medicare and Medicaid Services has proposed cutting reimbursement rates for proton beam therapy by approximately 30 percent under the Medicare Physician Fee Schedule, a change that providers say would eliminate the financial margin needed to keep freestanding proton centers operational. The proposed rule, published in the Federal Register as part of CMS's annual fee schedule update process, applies the same clinical reimbursement rate to proton therapy regardless of whether the treatment is delivered at a hospital outpatient department or a freestanding center.
Proton therapy is a form of radiation treatment that uses charged particles rather than conventional X-rays to target tumors. Proponents of the technology argue that its precision reduces the dose of radiation absorbed by surrounding healthy tissue, a factor with particular clinical relevance for pediatric patients, whose developing organs are more sensitive to incidental radiation exposure. The American Society for Radiation Oncology has published clinical guidance noting that proton therapy carries dosimetric advantages in specific cancer types, including pediatric brain tumors and certain head and neck cancers.
The reimbursement question turns on cost structure. Proton therapy facilities require cyclotrons or synchrotrons to generate the particle beams, equipment that costs between $100 million and $200 million to install, according to capital cost disclosures filed by publicly traded hospital systems with the Securities and Exchange Commission. Freestanding centers, which do not have the cross-subsidy revenue of a full hospital campus, argue that a 30 percent rate reduction would push per-treatment reimbursement below the operational cost floor.
CMS sets physician and facility fee schedule rates annually through a notice-and-comment rulemaking process governed by the Administrative Procedure Act. The agency accepts public comment on proposed rules for a standard period before issuing a final rule, typically effective January 1 of the following year. The deadline for public comment on the relevant rule cycle is available on the CMS website and in the Federal Register notice.
Providers operating freestanding proton centers have submitted formal comments to CMS opposing the rate structure. The Washington Examiner published an opinion piece on September 27, 2026, authored by a physician at the Southwest Florida Proton Center, describing the clinical implications for pediatric patients and arguing that the rate cut would force rural and suburban centers to close, leaving patients in those areas without access to the treatment. The piece does not constitute a CMS filing but represents the category of public comment the agency is required to consider under APA rulemaking.
Access geography is a documented concern in the proton therapy debate. As of the most recent National Association for Proton Therapy directory, the United States has approximately 45 operational proton therapy centers. The majority are affiliated with academic medical centers or large hospital systems concentrated in major metropolitan areas. Freestanding independent centers make up a smaller subset and are more likely to be located in mid-sized cities or suburban markets.
The rate cut also intersects with a broader Medicare reimbursement structure issue. Under current law, the Medicare Physician Fee Schedule is subject to a budget neutrality requirement, meaning rate increases for some services must be offset by decreases elsewhere. CMS has not publicly specified in its proposed rule which budget neutrality offsets apply to the proton therapy adjustment, and that detail would be disclosed in the full proposed rule text published in the Federal Register.
Congress has the authority to override or modify CMS rate determinations through legislation. The Medicare Payment Advisory Commission, known as MedPAC, advises Congress annually on payment adequacy across Medicare service categories. MedPAC's most recent publicly available report on radiation oncology payment adequacy is accessible on the MedPAC website and would provide the independent benchmark against which the proposed rate can be evaluated.
The practical effect on patient access depends on how many centers would close or discontinue Medicare participation if the rule is finalized. That number is not yet public. A document that would provide clarity is an economic impact analysis, which CMS is required to conduct under the Regulatory Flexibility Act for rules with significant effects on small entities. Whether CMS has classified freestanding proton centers as small entities subject to that analysis is not stated in available public summaries of the proposed rule and would need to be confirmed in the full Federal Register text.
What remains unknown is the final rate CMS will set, which will not be determined until the agency issues its final Physician Fee Schedule rule, expected before January 1, 2027. Also unknown is whether any member of Congress has introduced legislation to establish a separate payment pathway for freestanding proton centers, which would appear in the congressional record and in the text of any introduced bill posted on Congress.gov.