If you are trying to figure out whether Medicare Part B covers Stelara, welcome to one of Medicare’s favorite hobbies: making one medication live in two different benefit worlds. Stelara, known by its generic name ustekinumab, is a biologic used for several inflammatory and autoimmune conditions, including Crohn’s disease, ulcerative colitis, plaque psoriasis, and psoriatic arthritis. It can be given as an intravenous infusion in some situations and as a subcutaneous injection in others. That tiny detailhow the drug is givencan decide whether Medicare treats Stelara like a medical benefit under Part B or a prescription drug benefit under Part D.
The short answer is this: Medicare Part B may cover the IV induction dose of Stelara when it is medically necessary and administered in a covered outpatient medical setting, especially for Crohn’s disease or ulcerative colitis. However, Medicare Part B generally does not cover the subcutaneous Stelara injections that patients usually take as maintenance therapy. Those injections are typically handled under Medicare Part D, if the drug is on your plan’s formulary and prior authorization is approved.
That answer sounds simple until you add Medicare Advantage, specialty tiers, prior authorization, biosimilars, deductibles, coinsurance, and the occasional phone tree that asks you to “listen carefully because our menu has changed.” Let’s break it down in plain English.
What Is Stelara?
Stelara is a biologic medication that targets interleukin-12 and interleukin-23, two proteins involved in inflammation. Doctors may prescribe it for moderate to severe autoimmune or inflammatory conditions when other treatments have not worked well enough, are not appropriate, or cause problems.
Stelara is approved for several conditions, including:
- Moderate to severe plaque psoriasis
- Active psoriatic arthritis
- Moderately to severely active Crohn’s disease
- Moderately to severely active ulcerative colitis
The important coverage detail is that Stelara is not always administered the same way. For Crohn’s disease and ulcerative colitis, treatment commonly begins with a one-time IV induction infusion based on body weight. After that, maintenance treatment is usually a subcutaneous injection given every eight weeks. For plaque psoriasis and psoriatic arthritis, Stelara is generally given as a subcutaneous injection from the start.
In Medicare language, this creates two different doors. The IV infusion may enter through the medical-benefit door. The self-injected maintenance dose usually enters through the prescription-drug door.
How Medicare Part B Usually Covers Drugs
Medicare Part B is medical insurance. It covers doctor visits, outpatient care, preventive services, durable medical equipment, and a limited group of outpatient prescription drugs. Part B drug coverage is not designed to cover every medication someone takes at home. Instead, it usually applies to drugs that are administered by a doctor or other healthcare professional as part of medical care.
Common examples of Part B-covered drugs include certain infusions, some injectable cancer medications, drugs used with durable medical equipment, and medications administered in a doctor’s office or hospital outpatient department. The key phrase is not usually self-administered. If Medicare determines that a drug is usually taken by patients themselves, it is generally excluded from Part B coverage, even if a patient would rather have a clinician give it.
That distinction matters for Stelara because subcutaneous Stelara injections are commonly self-injected or injected by a caregiver after proper training. Medicare contractors have treated these injections as usually self-administered, which means they are generally not paid under Part B.
So, Does Medicare Part B Cover Stelara?
The practical answer
Sometimes, but not usually for the version people think of first. Medicare Part B may cover Stelara when it is given as an IV infusion in a covered medical setting and meets Medicare’s medical-necessity requirements. This is most relevant for the initial induction dose used for Crohn’s disease or ulcerative colitis.
However, the ongoing subcutaneous Stelara injectionsthe maintenance doses many patients continue at homeare generally not covered by Medicare Part B. They are usually covered, if covered at all, under Medicare Part D or a Medicare Advantage plan’s prescription drug benefit.
Example: Crohn’s disease
Suppose a person with moderately to severely active Crohn’s disease starts Stelara. Their first dose may be an IV infusion at an outpatient infusion center or hospital outpatient department. Because that infusion is administered by healthcare professionals and is not something the patient normally gives themselves, it may be billed under Part B when all coverage rules are met.
Eight weeks later, the patient may switch to a 90 mg subcutaneous injection for maintenance. That injection is typically handled under Part D because it is a self-administered prescription medication. Same brand name, different route, different Medicare lane. Medicare loves lanes.
Example: plaque psoriasis
For plaque psoriasis, Stelara is generally prescribed as a subcutaneous injection. Since this form is commonly self-administered, Part B generally does not cover it. A Medicare Part D plan may cover it, but the plan may require prior authorization, place it on a specialty tier, or require use of a preferred alternative or biosimilar depending on the plan’s formulary rules.
Medicare Part D and Stelara Coverage
Medicare Part D is prescription drug coverage. It is offered through private insurance companies approved by Medicare. People with Original Medicare can enroll in a standalone Part D prescription drug plan, while many Medicare Advantage plans include drug coverage through an MA-PD plan.
Because subcutaneous Stelara is typically treated as a self-administered prescription medication, Part D is often the benefit that matters most for ongoing Stelara therapy. But Part D coverage is not automatic in the “walk into any pharmacy and stroll out whistling” sense. Stelara is an expensive specialty medication, and specialty drugs often come with extra plan controls.
A Part D plan may require:
- Prior authorization: Your prescriber must prove that Stelara is medically necessary.
- Specialty pharmacy use: The drug may need to come from a specific network specialty pharmacy.
- Quantity limits: The plan may limit how much can be filled at one time.
- Formulary review: The plan may prefer a biosimilar or alternative biologic.
- Step therapy in some plans: The plan may ask whether other treatments were tried first, though requirements vary.
In other words, seeing Stelara on a plan’s drug list is good news, but it is not the whole story. You also need to check the tier, restrictions, pharmacy network, and estimated out-of-pocket cost.
What You May Pay for Stelara Under Part B
If a Stelara IV infusion is covered under Original Medicare Part B, your costs generally follow Part B rules. In 2026, the standard Part B monthly premium is $202.90, and the annual Part B deductible is $283. After the deductible is met, beneficiaries usually pay 20% of the Medicare-approved amount for covered Part B services or items, assuming the provider accepts assignment.
That 20% can still be a serious number for a biologic medication. A Medigap policy may help cover some or all of that coinsurance, depending on the policy. Medicaid, retiree coverage, or other secondary insurance may also reduce costs for some beneficiaries.
For Medicare Advantage members, the cost may look different. The plan might charge a copay or coinsurance for the infusion, require prior authorization, and restrict coverage to in-network infusion centers. Medicare Advantage plans must cover Part A and Part B services, but they can use their own plan rules for networks and cost-sharing.
What You May Pay for Stelara Under Part D
Under Part D, costs depend heavily on the plan. In 2026, Medicare drug plans cannot have a deductible higher than $615, though some plans have a lower deductible or no deductible. After the deductible stage, many brand-name and specialty drugs may involve coinsurance rather than a flat copay.
Stelara has often been placed on specialty tiers in Part D plans. Specialty-tier coinsurance can make early-year costs feel like a financial ambush wearing a pharmacy badge. However, Medicare Part D now includes an annual out-of-pocket limit. In 2026, once your out-of-pocket spending on covered Part D drugs reaches $2,100, you enter catastrophic coverage and pay no additional out-of-pocket cost for covered Part D drugs for the rest of the year.
This cap can be especially important for patients who use high-cost medications like Stelara. It does not mean Stelara becomes cheap at the beginning of the year, but it may prevent unlimited cost exposure across the full year.
Can the Medicare Prescription Payment Plan Help?
The Medicare Prescription Payment Plan can help some people manage cash flow. It allows people with Medicare drug coverage to spread out-of-pocket prescription drug costs across the calendar year instead of paying a large amount all at once at the pharmacy.
This program does not lower the total cost of Stelara. Think of it as turning a steep staircase into a ramp. You still climb the same height, but it may feel less brutal on the kneesand the wallet.
This option may be useful for someone who expects to hit the Part D out-of-pocket limit early in the year. Before choosing it, beneficiaries should ask their plan how monthly bills would be calculated and whether it fits their budget.
Extra Help, Medicaid, and Manufacturer Support
People with limited income and resources may qualify for Extra Help, a Medicare program that helps pay Part D premiums, deductibles, coinsurance, and other drug costs. Some people qualify automatically, including those with full Medicaid, Supplemental Security Income, or help from a Medicare Savings Program.
Medicaid may also help with Medicare costs for people who qualify. Rules vary by state, so beneficiaries should contact their State Health Insurance Assistance Program, Medicaid office, or Medicare plan for guidance.
Manufacturer savings cards often exclude people with government insurance such as Medicare, but patient support programs may still provide benefits investigations, prior authorization support, or referrals to independent charitable foundations when available. These foundations can open and close based on funding, so timing matters. Calling once is good; calling back later can sometimes produce a different answer.
Why Coverage Can Change From One Year to the Next
Stelara coverage is not frozen in amber. Formularies change. Biosimilars enter the market. Plans renegotiate prices. Medicare rules evolve. A drug that was covered one way last year may be covered differently this year.
Another reason for confusion is that some patients remember a time when subcutaneous Stelara could be administered in a physician’s office and billed under Part B in certain situations. Recent Medicare contractor policies have shifted away from Part B payment for subcutaneous Stelara because it is considered usually self-administered. That means patients who once received it under Part B may now be directed to Part D coverage.
This shift can affect out-of-pocket costs, pharmacy logistics, and even where a patient receives treatment. For some people, Part D coverage may mean dealing with specialty pharmacy shipping, storage instructions, and prior authorization renewals. Not exactly glamorous, but very real.
How to Check Whether Your Medicare Plan Covers Stelara
The best way to confirm coverage is to check both the medical benefit and the pharmacy benefit. Do not assume that “Medicare covers Stelara” means every dose is covered the same way.
Step 1: Ask your doctor which form you are receiving
Ask whether your dose is an IV infusion or a subcutaneous injection. Also ask whether it is induction therapy or maintenance therapy. Those details can determine whether Part B or Part D is involved.
Step 2: Ask the billing office how it will be billed
If the medication is given in an infusion center, ask whether it will be billed under Medicare Part B, Medicare Advantage medical benefits, or another payer. Request an estimate before treatment when possible.
Step 3: Check your Part D formulary
Search for Stelara and ustekinumab on your plan’s drug list. Look for the tier, prior authorization requirements, quantity limits, and specialty pharmacy rules. Also check whether the plan prefers a biosimilar.
Step 4: Confirm prior authorization
For high-cost biologics, prior authorization is common. Your prescriber may need to submit diagnosis codes, treatment history, lab results, or notes showing why Stelara is appropriate.
Step 5: Ask about appeals and exceptions
If coverage is denied, ask why. A denial may be due to missing paperwork, an incorrect billing route, a formulary issue, or failure to meet medical-necessity criteria. Your doctor can often submit additional information or request an exception.
Common Reasons Stelara Claims Get Denied
Stelara claims may be denied for several reasons. Some are clinical; others are administrative. In plain English, sometimes the plan disagrees, and sometimes a form simply took a wrong turn in the paperwork jungle.
- The drug was billed under Part B when the plan considers it a Part D self-administered drug.
- The prescriber did not complete prior authorization.
- The plan requires documentation of diagnosis and previous therapies.
- The pharmacy is not in the plan’s specialty network.
- The plan prefers a biosimilar or alternative biologic.
- The dose or frequency does not match plan criteria.
- The patient’s plan changed at the start of the year.
The fastest fix is usually to identify the exact denial reason. “Not covered” is too vague. Ask for the denial code, written explanation, and appeal instructions.
Original Medicare vs. Medicare Advantage: Why It Matters
With Original Medicare, Part B and Part D are separate. A covered IV infusion may go through Part B, while self-injected Stelara usually goes through a standalone Part D plan. If you have Medigap, it may help with Part B coinsurance but will not pay Part D drug costs.
With Medicare Advantage, the plan bundles Part A and Part B benefits and often includes Part D drug coverage. That can make the plan easier to manage in one sense, but it also means you must follow the plan’s network, authorization, and pharmacy rules. An infusion center that is convenient may not be in network. A specialty pharmacy you used last year may not be preferred this year.
Before starting Stelara, Medicare Advantage members should ask the plan three questions: Is the infusion covered under the medical benefit? Is the injection covered under the pharmacy benefit? Which providers and pharmacies must I use?
Experience-Based Scenarios: What Patients Often Run Into
Here are realistic, experience-based scenarios that show how Stelara coverage can feel in daily life. These are composite examples, not personal medical advice.
Scenario 1: The first dose is smooth, then the pharmacy drama begins
A patient with ulcerative colitis receives the initial Stelara IV infusion at an outpatient center. The appointment is scheduled, the infusion is given, and the claim goes through the medical side of coverage. So far, so good. Eight weeks later, the patient expects the maintenance injection to work the same way. Instead, the doctor’s office says the next dose must come from a specialty pharmacy under Part D. Suddenly there is a new prior authorization, a shipping confirmation, a refrigerated package, and a copay estimate that needs careful review.
This situation is common because the route of administration changes. The patient did not change medications, but Medicare’s benefit category changed. The best move is to plan for the maintenance dose early, ideally right after the infusion, so the specialty pharmacy process does not delay treatment.
Scenario 2: The psoriasis patient learns Part B is not the main path
A person with plaque psoriasis asks whether Part B covers Stelara because the injection is expensive. Their dermatologist explains that Stelara for psoriasis is usually a subcutaneous injection. Since it is commonly self-administered, it normally goes through Part D, not Part B. The patient then checks the Part D formulary and discovers that prior authorization is required.
The dermatologist submits documentation showing disease severity, previous treatments, and why Stelara is appropriate. The approval comes through, but the plan requires use of a specialty pharmacy. The patient also asks about Extra Help and the Medicare Prescription Payment Plan to manage costs. The lesson: for psoriasis, the coverage conversation should usually start with the Part D formulary, not the Part B medical benefit.
Scenario 3: A plan change resets the paperwork
A beneficiary used Stelara successfully last year, then changed Medicare plans during open enrollment to save on premiums. In January, the specialty pharmacy says a new prior authorization is needed. The patient is frustrated because nothing changed medically. But from the new plan’s viewpoint, everything changed administratively.
This is why people taking specialty medications should review formularies every fall. A lower monthly premium can be wiped out quickly if the new plan has tougher restrictions, a different specialty pharmacy, or less favorable coverage for Stelara or its alternatives.
Scenario 4: The bill looks wrong because it went through the wrong benefit
A patient receives a notice showing a surprising cost. After several calls, they learn the claim may have been processed under the wrong benefit. The injection was treated as a medical claim when it should have gone through Part D, or the infusion was not properly authorized under the medical benefit.
When this happens, patients should ask the provider, pharmacy, and plan to confirm the billing route. The magic words are: “Was this processed under Part B, Part D, or my Medicare Advantage medical benefit?” That one question can save hours of confusion.
Bottom Line: What Readers Should Remember
Medicare Part B does not usually cover the subcutaneous Stelara injections that many patients use for maintenance therapy. Those injections are typically covered under Medicare Part D when the plan includes Stelara or an ustekinumab product on its formulary and approves any required prior authorization.
Medicare Part B may cover Stelara when it is given as an IV infusion in a covered medical setting, most commonly as the induction dose for Crohn’s disease or ulcerative colitis. The exact answer depends on your diagnosis, how Stelara is administered, where it is administered, your Medicare setup, and your plan’s rules.
The smartest approach is to verify coverage before treatment begins. Ask your prescriber what form of Stelara you will receive, ask the billing office how it will be billed, check your Part D formulary, and confirm prior authorization. Medicare may be alphabet soup, but with the right questions, you can at least find the spoon.
Note: This article is for general educational purposes. Medicare coverage, formularies, prior authorization rules, and drug costs can change. Always confirm coverage directly with Medicare, your Medicare Advantage plan, your Part D plan, your prescriber, or your pharmacist before starting or continuing Stelara.