Stelara Biosimilars and Medicare 2026
Stelara Biosimilars and Medicare 2026
Stelara Biosimilars Are on Medicare Now: What You Need to Know Before Your Next Refill
5 minute read
If you take Stelara (ustekinumab) for Crohn's disease, ulcerative colitis, plaque psoriasis, or psoriatic arthritis, 2026 is bringing changes to how Medicare covers your medication. Biosimilar versions of Stelara are now available and appearing on Medicare Part D formularies, and the Inflation Reduction Act has added another layer of complexity: ustekinumab is one of the first drugs with a federally negotiated Medicare price. Understanding what this means for your coverage, your cost-sharing, and your rights is something you want to do before your next refill, not after a denial notice arrives.
What Changed in 2026
Stelara's period of biologic exclusivity ended, and multiple biosimilar versions of ustekinumab have entered the market. At the same time, the Centers for Medicare and Medicaid Services selected ustekinumab as one of the drugs subject to Medicare drug price negotiation under the Inflation Reduction Act.¹
The negotiated Medicare price for ustekinumab takes effect in 2026. CMS published the Maximum Fair Price for ustekinumab following the negotiation process, and this price applies to the reference product (Stelara) dispensed to Medicare Part D beneficiaries.² Biosimilar versions of ustekinumab are not subject to the same negotiated price, but they are entering the market at prices that compete with the negotiated rate.
What this means practically: your Part D plan now has several versions of ustekinumab to choose from when building its formulary. Some plans will cover the reference product Stelara at the negotiated price. Others will cover one or more biosimilar versions at their own negotiated rates. A few plans may only cover biosimilars and require a prior authorization or medical exception for Stelara. Every plan is different, and no two Part D formularies look exactly alike.
Will Your Plan Force You to Switch to a Biosimilar?
The short answer is: it depends on your specific plan, and the rules here matter.
Medicare Part D plans have significant latitude in how they build their formularies. A plan may cover biosimilar ustekinumab on a preferred tier and place Stelara on a non-preferred tier with higher cost-sharing, effectively making the reference product more expensive. A plan may also require step therapy, meaning you would need to try a biosimilar first before the plan will approve Stelara.
What Medicare plans cannot do is remove a drug from the formulary mid-year without triggering specific patient protections. If you are currently enrolled in a Part D plan that covers Stelara and your plan changes its coverage mid-year, you have the right to a transition supply and the right to request a formulary exception.³
If you are starting a new plan year in 2026 and your plan's formulary has already changed, your options include requesting a formulary exception (showing medical necessity for the specific drug), requesting an exception to the tiering structure (to get Stelara at a lower cost-sharing level), or filing an appeal if you receive a denial.
The IRA Negotiated Price and What It Actually Changes
The Inflation Reduction Act's drug price negotiation program has been described as transformational, and the 2026 negotiated prices for the first ten drugs are now in effect. Ustekinumab is among them. According to DLA Piper's analysis of the IRA negotiation program, the Maximum Fair Price for negotiated drugs can represent substantial reductions from the list price.⁴
However, what matters to you at the pharmacy is not the list price or even the Maximum Fair Price in isolation. What matters is how your plan translates that negotiated price into your actual out-of-pocket cost. Your cost-sharing depends on your plan's tier structure, whether you have met your deductible, and where you are in the Part D coverage phases.
One significant 2026 change that benefits all Medicare Part D beneficiaries is the $2,000 annual out-of-pocket cap established by the IRA. Once you have paid $2,000 in covered drug costs in a calendar year, you pay nothing more for covered drugs for the rest of the year.⁵ For patients on high-cost biologics like Stelara, this cap is meaningful protection.
What This Means for You
Before your next Stelara refill, take these concrete steps.
Check your plan's current formulary at Medicare.gov or by calling your plan's member services line. Look for how Stelara (ustekinumab) is listed, which tier it is on, and whether biosimilar versions are listed alongside it.
If your plan now requires a biosimilar first, talk to your prescribing physician. If you are stable and doing well on Stelara, your physician may have clinical reasons to document why continuing the reference product is appropriate. That documentation forms the basis of a formulary exception request.
If you receive a denial for Stelara or for continued coverage at your previous cost-sharing level, you have the right to appeal. The appeals process for Medicare Part D includes multiple levels, starting with a redetermination request to your plan and escalating through an Independent Review Entity, the Office of Medicare Hearings and Appeals, and beyond if necessary.³
Ellen can help you understand your denial and build your appeal. Start here
Frequently Asked Questions
Is a Stelara biosimilar the same as Stelara?
Biosimilars approved by the FDA have been shown to have no clinically meaningful differences from the reference product in terms of safety, purity, and potency. They are produced by different manufacturers using different cell lines and manufacturing processes, so they are not identical copies. For patients starting ustekinumab therapy, biosimilars are generally considered appropriate alternatives. For patients who are already stable on Stelara, the decision to switch involves clinical judgment from your prescribing physician.
Can my Medicare plan require me to switch to a biosimilar?
Medicare Part D plans can build their formularies in ways that favor biosimilars over the reference biologic, including placing Stelara on a higher cost-sharing tier or requiring step therapy with a biosimilar first. You have the right to request a formulary exception if you have a medical reason for the specific drug, and you can appeal a denial of that exception.
What is the $2,000 out-of-pocket cap and does it apply to Stelara?
Starting in 2026, Medicare Part D beneficiaries pay no more than $2,000 per year in out-of-pocket costs for covered drugs. This cap applies to drugs on your plan's formulary, including covered biologics and biosimilars. If Stelara or a covered biosimilar version of ustekinumab is on your formulary, your costs stop once you reach $2,000 for the year.
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