Does Medicare Pay for Proton Therapy?

Proton therapy is a specialized form of radiation treatment that precisely targets cancer cells using a beam of protons, rather than the X-rays used in conventional radiation therapy. This approach allows for a more concentrated delivery of radiation to the tumor, potentially reducing the dose to surrounding healthy tissues. This article explains the intricacies of Medicare coverage for proton therapy, including eligibility, costs, and the steps involved in securing treatment.

Medicare Coverage for Proton Therapy

Medicare generally provides coverage for proton therapy as a form of radiation treatment for cancer. Primary coverage typically falls under Medicare Part B, which addresses outpatient medical services. This includes initial treatment planning, simulation procedures to accurately map the tumor, and the actual delivery of proton beam therapy sessions.

If proton therapy is administered during an inpatient hospital stay, Medicare Part A, which covers hospital insurance, may be relevant. In such cases, Part A would help cover costs associated with the hospital admission itself, including facility charges. However, most proton therapy treatments are provided on an outpatient basis or in freestanding clinics, making Medicare Part B the main component of Original Medicare responsible for covering these services. Regardless of the specific Medicare part involved, the treatment must be deemed medically necessary for coverage to apply.

Medical Necessity and Specific Criteria

Medicare coverage for proton therapy is not automatic and hinges on a determination of medical necessity. The treatment must be appropriate and reasonable for the diagnosis and treatment of the patient’s specific illness or injury. Coverage often depends on several factors, including the patient’s specific cancer diagnosis, the type of cancer, its stage, and sometimes, their prior treatment history.

A physician’s recommendation and comprehensive supporting documentation are crucial for establishing medical necessity. Medicare typically covers proton therapy when sparing surrounding healthy tissue is not adequately achievable with traditional photon-based radiation therapy, and when the proton approach offers a clear benefit to the patient. This can apply in situations where the target area is close to critical structures, if the same or an immediately adjacent area has been previously treated with radiation, or when specific treatment doses are necessary to avoid excessive radiation hotspots. Certain conditions like solid tumors in children and central nervous system tumors are often considered strong candidates for proton therapy due to the precision it offers.

Understanding Costs and Out-of-Pocket Expenses

Even with Medicare coverage, beneficiaries will incur out-of-pocket expenses for proton therapy. For services covered under Medicare Part B, individuals are responsible for meeting an annual deductible, which is $257 in 2025. After the deductible is satisfied, Medicare typically pays 80% of the Medicare-approved amount for covered services, leaving the beneficiary responsible for the remaining 20% coinsurance. Since proton therapy is a high-cost treatment, this 20% coinsurance can amount to a significant financial responsibility.

If proton therapy requires an inpatient hospital stay, Medicare Part A covers the hospital costs, but a deductible of $1,676 per benefit period applies in 2025. Additionally, coinsurance amounts begin on day 61 of a hospital stay, increasing with the length of admission. Medicare Advantage (Part C) plans, offered by private companies approved by Medicare, also cover proton therapy, but their cost-sharing structures, such as copayments and deductibles, and network requirements can vary. Medigap (Medicare Supplement Insurance) plans can help cover some of the out-of-pocket costs, including the Part B coinsurance, providing additional financial protection for beneficiaries.

Steps to Secure Coverage and Treatment

Securing Medicare coverage for proton therapy involves several steps. The process begins with obtaining a referral from a physician who determines that proton therapy is the most appropriate course of treatment. For many Medicare Advantage plans, and sometimes with Original Medicare, a prior authorization may be required before treatment can begin. This involves the healthcare provider submitting documentation to the insurer for approval.

The provider’s team, often including financial counselors, will work to compile and submit all necessary clinical information and letters of medical necessity to Medicare or the Medicare Advantage plan. Clear communication with both the healthcare provider and the insurer is important throughout this process to understand the status of authorizations and any potential financial obligations. If a claim for proton therapy is denied, beneficiaries have the right to appeal the decision through a multi-level process. This requires explaining why the decision is disputed and providing additional supporting evidence, often with assistance from the medical team, within specific timeframes, such as 120 days for an initial appeal.