Yes, Medicare covers rituximab infusions under Part B for a range of FDA-approved conditions and several off-label uses. Because rituximab is administered by infusion in a medical setting rather than taken at home, it falls under Part B’s coverage of outpatient drugs. After you meet the annual Part B deductible ($257 in 2025), Medicare typically pays 80% of the approved amount, leaving you responsible for the remaining 20% coinsurance.
Conditions Covered Under Part B
Medicare covers rituximab for all four of its FDA-approved uses: non-Hodgkin lymphoma (NHL), chronic lymphocytic leukemia (CLL), rheumatoid arthritis, and two forms of blood vessel inflammation called GPA and MPA. For rheumatoid arthritis specifically, coverage applies when you’ve already tried at least one TNF-blocking therapy without adequate results. For the blood cancers, coverage extends across multiple stages of treatment, from first-line therapy through maintenance and retreatment for relapsed disease.
Off-Label Uses Medicare May Cover
Beyond FDA-approved conditions, Medicare’s regional contractors have approved rituximab for a notably long list of off-label uses. This is where coverage questions get more nuanced, because not every use of rituximab qualifies automatically. The approved off-label conditions include:
- Blood disorders: immune thrombocytopenia (ITP), Evans’ syndrome, Waldenstrom’s macroglobulinemia, autoimmune hemolytic anemia (when standard treatments have failed), and refractory thrombotic thrombocytopenic purpura
- Neurological conditions: multifocal motor neuropathy (as second-line therapy), relapsing-remitting multiple sclerosis (as third-line therapy), neuromyelitis optica, myasthenia gravis, and anti-MAG polyneuropathy
- Other conditions: polymyositis, graft-versus-host disease (as third-line therapy or later), and ANCA-associated vasculitis
For many of these off-label uses, coverage only kicks in after you’ve tried and failed other treatments first. Autoimmune hemolytic anemia, for example, requires that you’ve been through corticosteroids and possibly splenectomy before rituximab is considered covered. Medicare bases these off-label coverage decisions on recognized medical reference guides, called compendia, that evaluate clinical evidence for drug uses beyond what the FDA originally approved.
What You’ll Pay Out of Pocket
Rituximab is expensive, and even 20% coinsurance can add up quickly. A single infusion course for rheumatoid arthritis involves two infusions spaced two weeks apart, while cancer treatment schedules may call for four to eight infusions. Your 20% share of each infusion can amount to hundreds or even thousands of dollars depending on the dose and setting.
If you have a Medigap (Medicare Supplement) policy, most plans cover that 20% Part B coinsurance in full. Beneficiaries who qualify for Medicaid or certain Medicare Savings Programs also get help with cost sharing. Without supplemental coverage, the coinsurance for a biologic drug like rituximab is one of the larger out-of-pocket expenses you can face under Part B.
Where you receive your infusion also affects cost. Hospital outpatient departments charge facility fees on top of the drug cost, which increases your total bill compared to receiving the same infusion at a doctor’s office or freestanding infusion center. If your provider offers a choice of location, the non-hospital setting will generally cost you less.
Biosimilars Can Lower the Price
Three rituximab biosimilars are available in the U.S.: Truxima, Ruxience, and Riabni. These are near-identical versions of the original Rituxan, approved by the FDA as equally safe and effective. By 2022, biosimilars accounted for 60% of all rituximab claims paid by Medicare Part B, a dramatic jump from under 7% when they first entered the market in 2019.
The cost difference is real. Biosimilar pricing dropped 15% to 26% per dose in Medicare Part B between 2021 and 2022, while the brand-name version actually increased slightly. If your provider hasn’t already switched you to a biosimilar, it’s worth asking about. Medicare covers biosimilar rituximab under the same Part B rules as the original, and your coinsurance will be calculated on the lower price.
Medicare Advantage Coverage
If you’re enrolled in a Medicare Advantage (Part C) plan rather than Original Medicare, your plan is required to cover everything Original Medicare covers, including Part B drugs like rituximab. However, your cost sharing structure, network requirements, and prior authorization rules may differ. Many Medicare Advantage plans require prior authorization before approving rituximab infusions, meaning your doctor’s office will need to submit documentation showing the drug is medically necessary for your specific condition before treatment begins. You may also need to use in-network infusion centers or hospitals to get the best coverage rate.
Medical Necessity Requirements
Regardless of whether you have Original Medicare or Medicare Advantage, coverage for rituximab hinges on medical necessity. Your doctor needs to document that your diagnosis matches one of the covered conditions and, for many off-label uses, that you’ve tried and failed the required prior therapies. For cancer-related uses, your medical records should confirm the specific type and stage of disease. For autoimmune conditions like rheumatoid arthritis, records need to show inadequate response to previous treatments.
If a claim is denied, it’s often because the documentation didn’t clearly establish medical necessity rather than because the condition itself isn’t covered. Your provider can appeal the decision and submit additional records. You also have the right to request a coverage determination in advance if you want confirmation before starting treatment.