Tysabri (natalizumab) costs roughly $8,700 per infusion at list price. Given that the standard dosing schedule is one infusion every four weeks, that works out to 13 infusions per year and an annual drug cost of approximately $113,000 before insurance. What you actually pay, though, depends heavily on your insurance type, where you receive infusions, and whether you use financial assistance programs.
Cost Per Infusion and Annual Total
The listed price for a single 300 mg vial of Tysabri starts at about $8,681. That covers just the drug itself. On top of that, every infusion visit includes administration fees: the IV setup, nursing time, facility charges, and monitoring. These fees vary widely depending on where you get your infusion. Hospital outpatient centers tend to charge the most, while standalone infusion clinics and at-home infusion services are typically less expensive.
A 2023 analysis of real-world medical costs found that patients starting Tysabri saw their average total medical costs jump from about $53,000 the year before treatment to more than $117,000 in the first year and around $106,000 in the second year. The drug itself accounted for more than 78% of those costs, with the rest coming from administration and related medical expenses. Hospital outpatient infusions were the most common setting but also the most expensive, partly because facilities can add markups for profit, taxes, and overhead on top of the drug’s price.
What You Pay With Insurance
Most people receiving Tysabri have either commercial insurance or Medicare, and the out-of-pocket cost differs significantly between the two.
Commercial Insurance
With employer-sponsored or marketplace insurance, your cost depends on your plan’s coinsurance rate and annual out-of-pocket maximum. Many plans cover Tysabri as a medical benefit (not a pharmacy benefit) because it’s administered by infusion. You’ll typically owe a percentage of the allowed amount per visit until you hit your plan’s out-of-pocket cap. For a drug at this price point, most commercially insured patients reach their annual maximum within the first few infusions, meaning the remaining infusions for the year are fully covered.
Medicare Part B
Tysabri is generally covered under Medicare Part B as a physician-administered drug. After meeting the annual Part B deductible, you’re responsible for 20% of the Medicare-approved amount. At roughly $8,700 per infusion, that 20% coinsurance comes to about $1,740 per dose, or more than $22,000 per year, if you don’t have supplemental coverage. A Medigap policy or Medicare Advantage plan can significantly reduce that burden. It’s also worth noting that Part B coinsurance may be lower for certain drugs whose prices have risen faster than inflation, though whether Tysabri qualifies depends on current pricing benchmarks.
How Tysabri Compares to Other MS Treatments
Tysabri’s costs are broadly comparable to other high-efficacy infused MS therapies. Ocrevus (ocrelizumab), one of its main competitors, had even higher real-world costs in the same 2023 analysis: average total medical spending exceeded $125,000 in the first year of treatment, with insurers paying about 60% more than the drug’s list price due to hospital markups. Tysabri’s first-year costs of $117,000 were slightly lower, though both drugs represent a major financial commitment. At-home infusions, where available, tended to cost less for both treatments compared to hospital outpatient settings.
Financial Assistance Programs
Biogen, the manufacturer, offers two programs that can substantially lower out-of-pocket costs for commercially insured patients.
- Biogen Copay Program: Available to commercially insured patients with no income requirements and no enrollment time limit. There is an annual cap on the total assistance provided, but for many patients this program covers all or most of their coinsurance after the first infusion.
- Administration Copay Assistance: Covers up to $250 toward facility and administration fees at each infusion visit, with an annual out-of-pocket maximum of $3,250. This is separate from the drug copay program and helps offset the infusion center charges that insurance may not fully cover.
Neither program is available to patients on Medicare, Medicaid, or other government insurance. If you have government coverage, independent nonprofit foundations sometimes offer grants for MS treatments, though funding varies throughout the year and isn’t guaranteed.
Ways to Lower Your Cost
Beyond manufacturer programs, a few practical strategies can reduce what you pay. Choosing a freestanding infusion clinic over a hospital outpatient department often cuts administration fees significantly, sometimes by hundreds of dollars per visit. If your insurer covers home infusion, that can be even cheaper. Ask your neurologist’s office or the TOUCH prescribing program (the required enrollment system for Tysabri) about site-of-care options in your area.
If you’re commercially insured, review your plan’s out-of-pocket maximum carefully. Plans with lower annual caps mean you’ll stop paying coinsurance sooner in the year. Some patients strategically schedule their first infusion early in January to maximize the months of fully covered treatment after hitting their deductible and out-of-pocket limit. For Medicare patients without supplemental insurance, contacting a Patient Access Navigator through Biogen or an MS advocacy organization can help identify foundation grants or state programs that offset coinsurance costs.