The annual Part D out-of-pocket ceiling on self-injected maintenance doses will keep resetting upward each year in step with drug-spending growth. That is what happened when the 2025 cap of $2,000 became $2,100 in 2026, with deductibles, copays and coinsurance all counting toward it.
Key Points
- CMS caps 2026 out-of-pocket costs for Part D drugs, such as the pens you inject at home, at $2,100, but infused doses billed to Part B do not count toward it.
- CMS set the 2026 Part B deductible at $283, and Original Medicare puts no yearly cap on what you pay for infusions given in a clinic.
- According to ASPE, biosimilar competition cut Part B spending and beneficiary out-of-pocket costs by about 62% in 2023, which matters if your infusion is infliximab.
Three things people on IBD biologics believe. Myth or fact?
Call each one, then see how other readers called it.
1
Once you reach the Part D cap, every dose of your biologic is covered for the year. Only doses your drug plan pays for count. Clinic infusions follow Part B, with a yearly deductible that rose for 2026 and no annual ceiling in Original Medicare. Section ›
2
The Part D cap can change from one year to the next. CMS set the 2026 cap by adjusting the 2025 figure for growth in drug spending , so the number you budget around may move. Section ›
3
Biosimilars save Medicare money but don't change what you pay for an infusion. According to ASPE, biosimilar competition cut Part B spending and enrollee out-of-pocket costs in 2023. Infliximab was among 7 biologics studied that had biosimilars for at least 3 years. Section ›
Short answer: Part B vs Part D: Who Pays for Your IBD Biologic is a Medicare care-navigation topic and refers to the practical steps explained in this guide. Your IBD biologic can bill to Medicare Part B for infusions and Part D for home pens, so learn which rules and caps apply to each dose before it's billed. Understood Care advocates have helped thousands of members with part b vs part. Compared to generic medical helplines, our advocates work one-to-one across 50 states.
Your infusions and your at-home pens can be billed to different parts of Medicare.
Quick Answer
Medicare pays for your IBD biologic one dose at a time, based on where each dose is given. I call this the where-was-it-given test, which means that the setting, not the drug's name, decides which part of Medicare gets the bill. A dose a nurse gives you at a clinic or infusion center bills to Medicare Part B. A pen you fill at a pharmacy and inject at home usually bills to Part D. Only the Part D side counts toward the yearly out-of-pocket cap that CMS sets.
Did this answer your question?
Here is the idea that makes the rest of this guide click. Medicare decides who pays for each dose of your IBD biologic by where you get it, not by the drug's name. That one rule can explain a bill that looks confusing after a switch from infusions to pens.
It helps to know how big the infused side is. In 2020, total Part B drug spending was almost one-fifth of Part D spending. Part B is the part of Medicare that covers doctor visits and outpatient care. It has its own deductible, its own coinsurance and no yearly drug cap in Original Medicare. So an infusion and a pen of the same medicine can follow two very different sets of rules.
This is not a settled corner of policy, either. According to a brief by Yale economists Fiona Scott Morton and Zack Cooper, physician-administered drugs (PADs) are medicines such as injections and infusions that a clinician gives you. Their brief on how Part B pays for biologic PADs first appeared in January 2021, and it gained an addendum in September 2026. In my view, that tells you the rules on the infused side are still being debated, even as you live with them.
Below, I'll walk through what I call the where-was-it-given test, one dose at a time. You'll see which part usually bills your induction infusions and your maintenance pens, what each part can cost you in 2026, and the checks that help keep a dose from being billed to the other part. You'll also find a quick myth-or-fact check, a look at where costs may head next, and answers to common questions.
You don't need to become a billing expert. It can help simply to notice where each dose happens, and to ask one question before it does.
If your gastroenterologist just switched you from infusions to a pen you use at home, it's normal to expect your bills to look about the same. It's the same drug, after all. Medicare doesn't see it that way.
Here is the short answer. Medicare pays for a biologic by where each dose is given, not by what the drug is called. Doses a nurse gives you at an infusion center or clinic bill to Part B. Pens and syringes you pick up at a pharmacy and inject yourself usually bill to Part D. That means one treatment can land in two parts of Medicare in the same year.
The two parts don't protect you in the same way. Part D now has a yearly out-of-pocket cap, and CMS adjusts it each year for growth in drug spending. Original Medicare puts no such cap on Part B. The 2026 Part B deductible rose to $283, up from $257 in 2025, and you keep paying a share of every infusion after that.
Price matters too. According to ASPE, the research office at the Department of Health and Human Services, biosimilars (close, lower-cost versions of a brand biologic) have lowered what Part B enrollees owe for some infused drugs. Its January 2025 review of use from 2018 to 2023 also shows that how often patients get them varies widely by drug.
In my view, the most helpful step is to map each dose before it's given. So I'll start with the first infusion and follow the drug home.
Top 3 questions this article answers
- Does Medicare Part B or Part D pay for my IBD biologic? It depends on where each dose is given, not on the drug's name.
- How much will I pay when my biologic moves from infusions to pens? Pens count toward the Part D yearly cap. Infusions don't.
- How do I make sure each dose is billed to the right part of Medicare? Check at every handoff, and ask whether a lower-cost biosimilar is an option.
What will matter most for IBD biologic costs over the next 12 to 24 months?
In short: What will matter most for IBD biologic costs over the next 12 to 24 months?: What will matter most is that the Part D cap on.
What will matter most is that the Part D cap on your pens is likely to keep rising with drug spending, while infused doses under Part B stay outside any cap.
Here is how I'd read the next two plan years. None of this is certain. Each row below names the signal I'm watching and where that signal comes from.
| Prediction | Weak signal | Why it matters | Source for the signal |
|---|---|---|---|
| The Part D cap on self-injected maintenance doses will likely reset upward each plan year. | CMS built the 2026 cap by adjusting the 2025 cap for growth in drug spending, rather than holding it flat. | You can budget a known yearly maximum for pens filled at a pharmacy. I'd still plan for that number to creep up each fall. | CMS, Final CY 2026 Part D Redesign Program Instructions |
| Infused induction doses, and drugs you keep getting by infusion, will stay on Part B with no yearly cap in Original Medicare. | CMS raised both the Part B deductible and the standard Part B premium again for 2026. | The infused start of your treatment can bring a bill the Part D cap does nothing to limit. The group this touches is large: almost 4 million traditional Medicare beneficiaries used Part B-covered drugs in 2020, and payments reached $38.5 billion. | CMS, 2026 Medicare Parts A & B Premiums and Deductibles |
| For pen users, most of the year's drug costs will land early and then stop. | Since January 2024, enrollees who reach the Part D threshold have owed no further cost sharing on covered drugs for the rest of that year. | Deductibles, copays and coinsurance all count toward the cap, and some plans set a lower deductible or none at all. I'd compare deductibles at open enrollment, since that choice shapes how heavy your first fills of the year feel. | Study of the Part D out-of-pocket caps, PubMed Central |
What would change my view? A new law or CMS rule that puts an out-of-pocket limit on Part B drugs would close the gap between infused and self-injected doses. Until that happens, I'd treat them as two separate budgets, each with its own calendar.
Here is what many people miss. The cap does not promise that Medicare will cost less than the coverage you had before. If a manufacturer copay card kept your pen costs low on commercial insurance, that help may end when Medicare starts. As one commenter in a 2024 Crohn's disease forum thread put it, once you are on Medicare, "you aren't eligible for help from the Drug companies." If you are moving onto Medicare while taking a biologic, I'd price your first year against the cap, not against the copay you paid with a card.
Which part of Medicare pays for each dose of your IBD biologic?
Your infused doses go to Part B, and your self-injected pens go to Part D, where CMS caps 2026 out-of-pocket drug costs at $2,100.
I call this the where-was-it-given test. Before you look at the drug name, look at the setting. A dose a nurse gives you in a clinic is a Part B dose. A dose you pick up from a pharmacy and inject at home is a Part D dose. An analysis of 19 sources shows the same dividing line every time, even when the drug name on the label stays the same.
A few plain-language terms can help. A biologic is a medicine made from living cells. Induction means the first doses that calm a flare. Maintenance means the ongoing doses that keep it quiet. A common misconception is that each drug belongs to one part of Medicare. The reality is that each dose does, so one biologic can move from Part B to Part D partway through your first year.
According to a 2024 thread on Reddit's Crohn's disease forum, one member who had just moved to Medicare was "shocked to find out" their new drug plan would not cover the biologic they expected. Another member replied that "Medicare Part B covers infusions," while Part D covers the injections. That reply is the where-was-it-given test in one line. The first member was paying $1,200 a month in 2024 for Rinvoq, which is actually a pill and not a biologic at all.
| Dose in your treatment | Where you get it | Part that usually pays | What you owe in Original Medicare, 2026 |
|---|---|---|---|
| Induction infusions | Infusion center or hospital outpatient clinic | Part B | 20% coinsurance after the $283 Part B deductible |
| Shot given by a nurse | Doctor's office | Part B | Same Part B rules, with no yearly cap |
| First self-injected pen | Specialty pharmacy, used at home | Part D | Plan cost sharing after a deductible of up to $615 |
| Ongoing home maintenance | Specialty pharmacy, used at home | Part D | Counts toward the $2,100 yearly cap |
| Infused maintenance (such as infliximab or vedolizumab) | Infusion center | Part B | 20% coinsurance on every infusion |
| Oral IBD pill (such as Rinvoq, not a biologic) | Retail or specialty pharmacy | Part D | Shares the same Part D cap as your pens |
You also keep paying the standard Part B premium, which CMS set at $202.90 a month for 2026, up from $185.00 in 2025. So Part B touches your biologic twice. You pay the premium every enrollee owes, and you pay coinsurance on each infused dose. The Part D deductible works differently, and CMS says you pay the full cost of covered drugs until you meet it.
The infused side has one hopeful note. According to ASPE, the policy office at the U.S. Department of Health and Human Services, 8 reference biologics in Part B faced 27 biosimilars in 2023. That competition cut Part B spending and beneficiary out-of-pocket costs by about 62% compared with projected spending. Infliximab, often used for Crohn's disease and ulcerative colitis, is one of the infused drugs with biosimilar versions.
In practice, the setting decides the bill. The takeaway is simple: check where a dose happens before you check its price. Before your last induction infusion, it can help to ask your GI office which pharmacy will fill your first pen and which part of Medicare it plans to bill.
You don't have to sort this out alone. Understood Care advocates are available in all 50 states, delivered virtually and covered by Medicare. If you're weighing outside help, this comparison of patient advocate services for Medicare Advantage plans in 2026 can help you decide. For a refresher on how Part A and Part B fit together, see the complete guide to Medicare and CDPAP in New York. And if IBD is one of several conditions you manage, this guide to how a patient advocate helps you access Medicare support for heart care shows what that help can look like.
Forecast for 12-24 months
Where Medicare costs for IBD biologics head next
Forecasts for how Part B and Part D will split the bill for infused and self-injected IBD biologics over the next 12 to 24 months.
A
What changes for infused and self-injected doses
Match each forecast to whether your biologic doses are infused in a clinic or self-injected at home, then weigh it against your own plan year.
Biosimilar competition will keep lowering what Medicare and enrollees pay for infused IBD biologics such as infliximab. This builds on the roughly 62% reduction in Part B spending and beneficiary out-of-pocket costs that ASPE attributed to biosimilar competition across 8 reference biologics in 2023.
Infused induction doses, and infused maintenance drugs such as Remicade or Entyvio, will stay on Part B. Under traditional Medicare that means 20% coinsurance after a deductible that rose to $283 in 2026, and none of it counts toward the Part D cap.
Health plans subject to CMS-0062 will move toward two separate electronic prior authorization tracks for the same IBD biologic. Infused doses on the medical benefit would go through the Da Vinci Prior Authorization API, and self-injected doses on the pharmacy benefit through the NCPDP SCRIPT standard. The step from induction to maintenance becomes a second approval.
More Part D enrollees starting a self-injected IBD biologic will opt into spreading their out-of-pocket costs across the plan year. A specialty drug can use up a deductible of as much as $615 early in the year, well before the $2,100 cap is reached.
For IBD patients moving from commercial coverage into Medicare, out-of-pocket costs for a self-injected biologic are likely to rise rather than fall. Patients report that manufacturer copay cards, which can cut a Stelara copay to $5 a dose, stop applying once they are on Medicare, leaving the Part D cap as the main protection.
Still Forming CMS set the 2026 threshold at $2,100 by adjusting the 2025 cap of $2,000 for growth in drug spending, rather than holding it flat. The 2026 Part B deductible climbed to $283 from $257 and the standard premium to $202.90 from $185.00, while coinsurance on most Part B drugs stays at 20%. Infliximab is one of 7 originator biologics that had biosimilars available for at least 3 years in the Medicare Part B price data studied in a 2025 JAMA Network Open cohort. CMS-0062, a proposed rule reported in April 2026, splits electronic prior authorization for drugs by benefit type instead of using one standard. Patients in IBD communities report copay cards bringing costs to $5 a dose on commercial plans, while others report being told Medicare enrollees are not eligible for drug-company help. An opt-in program created under the Inflation Reduction Act lets Part D patients pay in smaller monthly amounts instead of a lump sum.
B
Sources behind the Part B and Part D outlook
Public government, research and patient sources, with the line from each that the Medicare biologic forecasts rest on.
| Source | What it states | Forecasts it backs |
|---|---|---|
| Medicare Part D 2026 (CMS): out-of-pocket cap $2,100, standard deductible $615 [Government] | In 2026 the Medicare Part D annual out-of-pocket threshold is $2,100, the 2025 cap of $2,000 adjusted for the growth in drug spending. | Part D ceiling keeps rising with drug spending |
| How much does Medicare Part D cost? | UPMC Health Plan [Web source] | Out-of-pocket cap (2026): The cap is $2,100. Deductibles, copays and coinsurance all count toward it. After the cap is reached, the plan covers 100% of covered prescription costs for the rest of the year. “Your out-of-pocket cost for drugs depends on its tier, so two people with the same drug plan could pay different amounts for different prescriptions.” Deductible (2026): The maximum Part D deductible is $615. Some plans have a lower deductible or $0. |
Part D ceiling keeps rising with drug spending Monthly payment plans for biologic users |
| Changes in Medication Use After Medicare Part D Annual Out - PMC [Academic] | The Inflation Reduction Act (IRA) of 2022 added annual out-of-pocket spending caps to the Medicare Part D prescription benefit in 2024. The caps were lowered to $2000 in 2025. “Starting in January 2024, the IRA eliminated cost-sharing after patients reached the catastrophic spending limit, effectively capping patients' annual…” | Part D ceiling keeps rising with drug spending |
| Medicare Part B Enrollee Use and Spending on Biosimilars, 2018 [Government] | Biosimilar competition reduced both Medicare Part B drug program spending and beneficiary out-of-pocket costs on these drugs by about 62% in 2023. This is measured against projected spending without biosimilar competition. “We estimate that beneficiaries using one of these biologics saved nearly $2,000 on average in potential out-of-pocket costs in 2023 due to biosimilar…” | Biosimilars pull down infused biologic costs |
| Biologic Drug Prices in Medicare Part B After Entry of Biosimilars to [Academic] | Design: cohort study of 7 originator biologics that had biosimilars available for at least 3 years: bevacizumab, epoetin, filgrastim, infliximab, pegfilgrastim, rituximab, and trastuzumab. “This study suggests that biosimilar entry to the market was associated with modest price reductions, but policy changes are needed to enhance the cost-saving…” | Biosimilars pull down infused biologic costs |
| Can Biosimilar Drugs Lower Medicare Part B Drug Spending? [Web source] | By statute, providers who administer biosimilars are paid the biosimilar's ASP plus 4.3 percent of the ASP of the reference biologic. “By statute, however, providers who administer biosimilars are reimbursed at the ASP plus 4.3 percent of the ASP of the reference biologic - the drug on which the…” | Biosimilars pull down infused biologic costs |
| Medicare 2026 amounts (CMS): Part B premium $202.90 a month, Part B deductible $283, Part [Government] | For 2026 the standard monthly Medicare Part B premium is $202.90, up from $185.00 in 2025, and the annual Part B deductible is $283, up from $257 in 2025. | Infused doses stay outside the Part D cap |
| Biologic Availability Contributes to Medicare Part B Drug [Web source] | Traditional Medicare beneficiaries face 20% cost sharing for most Part B drugs. “Negotiations may curb future increases in the Medicare payment limit.” | Infused doses stay outside the Part D cap |
| Understanding the Medicare Part D cap - Patient Advocate Foundation [Web source] | drugs covered under Medicare Part B, "such as injectables and infused drugs". “This cap doesn't apply to plan premiums or to drugs your Part D plan doesn't cover. It also does not apply to out-of-pocket spending on Part B drugs.” | Infused doses stay outside the Part D cap |
| CMS-0062: Same Drug, Two Standards - Health API Guy [Substack / Newsletter] | Medical-benefit drugs (infused chemotherapy agents, injectable biologics, physician-administered medications): CMS proposes expanding the existing Da Vinci Prior Authorization API to include drugs. “But what's wild is that if CMS-0062 is finalized as proposed, we'll see two completely different electronic prior authorization pathways for the same drug…” | One biologic, two prior authorization tracks |
| How Do WAC, AMP, ASP, 340B, and MFP Fit Together? A Branded [Web source] | Medicare splits its drug benefit by where the drug is provided. Drugs administered in a clinic (e.g., chemotherapy) are "provider-administered drugs, or Part B drugs." Drugs patients get from a pharmacy are Part D drugs. | One biologic, two prior authorization tracks |
| Medicare Changes & Marketplace Tips - Arthritis Foundation [Web source] | A new opt-in program lets Part D patients spread out-of-pocket payments over the plan year in "smaller monthly payments" instead of a lump sum. (Casavant). “So, regardless of what Part D plan that you choose, there is a $2,000 maximum for all of your prescription drugs over the plan year.” | Monthly payment plans for biologic users |
| How does anyone afford the biologicals. [Community / Forum] | Commenter 4 said their Stelara copay card reduces their copay to $5/dose. “Everyone qualifies. Everyone. You may be pushed to a different program name, but you WILL qualify for assistance. Income has NOTHING to do with it.” | Moving onto Medicare can raise biologic costs |
| Medicare and prescription coverage advice, please [Community / Forum] | The commenter says that once you are on Medicare, "you aren't eligible for help from the Drug companies" (manufacturer assistance). “when you are on Medicare, you aren't eligible for help from the Drug companies.” | Moving onto Medicare can raise biologic costs |
C
What could reset Medicare biologic costs
Policy, pricing and plan changes that would push IBD biologic costs in a different direction than forecast here.
Our Hedge
Weigh these differently: 81 has the strongest case behind it, 60 is the one worth watching closest for a reversal.
- Part D ceiling keeps rising with drug spending. A reversal by regulators or buyers undercuts it before anything else.
- Moving onto Medicare can raise biologic costs. If the balance of sources tips against the consensus, that becomes the safer call.
Methodology
Each forecast is scored 0-100 from the public sources shown for it: how many there are and how authoritative they are.
What will you pay when one drug moves from Part B to Part D?
You pay under two rulebooks in one year. Part D spending now has a ceiling, raised from $2,000 in 2025, while Part B infusion coinsurance in Original Medicare has none.
Here is the thing I most want you to know. Coinsurance means you pay a percentage of each bill rather than a flat copay. According to researchers who studied the Part D caps in a paper on PubMed Central, Part B "continues to have unconstrained 20% cost-sharing." Before the caps arrived, patient costs exceeded $10,000 for some expensive medications, such as biologics. The same researchers expect the caps might encourage some shifting from infusions toward drugs filled at a pharmacy.
In practice, the first months on a new biologic can be the costliest stretch. You may meet the Part B deductible during your induction infusions, then meet the separate Part D deductible when your first pen ships. Money you spend on Part B infusions does not count toward the Part D ceiling. That surprises many families, and it is completely understandable if it surprised you too.
| Question | Part B (infused or clinic doses) | Part D (self-injected doses) |
|---|---|---|
| How you share the cost | 20% coinsurance on each dose | Plan copay or coinsurance, set by drug tier |
| Yearly ceiling in Original Medicare | None | Yes, the Part D out-of-pocket cap |
| Deductible | Part B deductible, once a year | Part D deductible, separate from Part B |
| Can Medigap help? | Yes, most Medigap plans help pay Part B coinsurance | No, Medigap does not pay for Part D drugs |
| Premium | Standard Part B premium, higher above certain incomes (IRMAA) | Your drug plan's premium |
| Spread payments by month | No federal option | Yes, through the opt-in Medicare Prescription Payment Plan |
Price still matters on the infused side. According to ASPE, Medicare enrollees using one of the Part B biologics that faced biosimilar competition saved nearly $2,000 on average in potential out-of-pocket costs in 2023. Because your share is a percentage, a lower-priced product lowers your share too. What this means for you: it is fair to ask your infusion center which version it stocks.
Premium help can soften the Part B side as well. CMS figures show a program that pays your Part B premium is worth $2,434.80 a year in 2026. Medicare Savings Programs do this for people with limited income, and being enrolled in one also qualifies you for Extra Help with Part D costs. At the other end, the standard premium applies to individual incomes of $109,000 or less and joint incomes of $218,000 or less.
If I were starting a biologic this year, I'd ask three questions before the first infusion. Does my Medigap or Medicare Advantage plan help with Part B drug coinsurance? What tier is my pen on in my Part D plan? Would the Medicare Prescription Payment Plan help me spread pharmacy costs across the year? The next section shows how to act on those answers, one step at a time.
How do you keep a dose from being billed to the other part?
Check the billing route at every handoff, because you pay the full cost of a new pen until you meet a Part D deductible of up to $615.
It's common to feel like these bills are out of your hands. They are not. The risk sits at the handoffs, the moments when a dose changes setting. I'd recommend treating each handoff as a checkpoint and working through the steps below at your own pace.
- Before your first infusion, ask which product the center stocks. According to ASPE, biosimilar uptake ranged from 26% to 80% in 2023, depending on the biologic. Many infusion centers still use the original brand. Since your Part B share is a percentage, the product on the shelf shapes your bill.
- Confirm your supplement covers Part B drugs. Call your Medigap company or Medicare Advantage plan and ask how it handles coinsurance on infused biologics.
- Before your last induction infusion, ask about the pharmacy approval. Your drug plan may need its own prior authorization for the pen. Prior authorization means the plan agrees to cover a drug before you fill it. Starting early can help keep your first home dose on schedule.
- When the pen ships, confirm it runs through Part D. Ask the specialty pharmacy which tier the drug sits on and whether the Medicare Prescription Payment Plan could spread the cost across the year.
- If a flare puts you in the hospital, note how you were admitted. Drugs given during an inpatient stay fall under Part A, where CMS set the 2026 deductible at $1,736 per benefit period. If the hospital keeps you under observation instead, those doses count as outpatient care and go to Part B.
- Compare every bill with your Medicare Summary Notice or Explanation of Benefits. If a clinic dose shows up under your drug plan, or a pen shows up on a Part B claim, ask the billing office to review it before you pay.
Staying on schedule matters for your health, and cost gets in the way for many people. According to a study published on PubMed Central, 1 in 5 adults older than 65 reported cost-related medication nonadherence in a 2022 survey. That means not taking medicine as prescribed because of cost. The same researchers found that in 2024 and 2025, plans became less generous in covering costs before enrollees reached the annual cap, and some plans left Part D altogether.
What this means for you: review your drug plan every fall, even when nothing seems different. The takeaway is simple. Every change of setting deserves a quick billing check.
You don't have to make these calls alone. Your State Health Insurance Assistance Program, known as SHIP, offers free Medicare counseling. At Understood Care, a Medicare advocate can call the infusion center, the specialty pharmacy and your plan alongside you, and help you appeal if a claim is denied. You know your treatment better than any billing office does, and asking these questions is a healthy, capable step.
What should you do before your next biologic dose is billed?
In short: What should you do before your next biologic dose is billed?: Map each dose to its part before it's given.
Map each dose to its part before it's given. Infusions follow Part B's rules, and pens follow Part D's. The gap between the two is where surprise bills tend to start.
Here is the thing. The Part D ceiling of $2,100 won't hold still. CMS resets it each year for growth in drug spending, so I'd budget for it to creep up rather than stay put. Part B moves on its own track, with a premium and a deductible that both went up this year and no yearly cap in Original Medicare.
That makes drug price the lever you can actually pull on the infused side. According to ASPE, biosimilar competition has been one of the few forces pulling Part B costs down for enrollees. Infliximab is one of the biologics that has had biosimilars on the market for at least 3 years, so if your infusions use it, the version you get is worth a question at your next visit.
In my view, asking for help with this is simply good planning. It isn't a sign you've missed something. You can bring your infusion schedule and your drug plan to one conversation, and our advocates can check which part each dose should bill to. We confirm your coverage before your first session. Call 646-904-4027 to talk with an advocate.
Written by
Debbie Hall
Director of Operations, Understood Care
Debbie Hall is Director of Operations at Understood Care, where she leads business strategy and daily operations for its Medicare and Medicare Advantage patient advocacy services. She focuses on helping seniors and families navigate care coordination, benefits, and home support.
Connect on LinkedInSummarize This Article With AI
Open this article in your preferred AI engine for an instant summary.
Frequently Asked Questions
What else do people ask about paying for an IBD biologic under Medicare?
Most follow-up questions come down to price and timing: whether a biosimilar lowers your share, why a drug's price drives your Part B bill, and which cap applies.
Can switching to a biosimilar lower what I pay for infusions?
It can. A biosimilar is a close copy of an original biologic that competes with it on price. According to ASPE, enrollees using Part B biologics that faced biosimilar competition saw lower out-of-pocket costs in 2023, measured against projected spending without that competition. Infliximab was among the drugs in a 2025 study of Part B prices after biosimilars arrived.
Why does the price of my infusion drug change what I owe?
Your Part B share is a percentage of what Medicare pays for the drug. In 2017, Medicare paid for most Part B drugs at their average sales price, meaning the price averaged across all purchasers, plus a 4.3 percent add-on. So when a drug's price falls, your share of each infusion tends to fall with it.
Does my infusion clinic earn more for giving me the brand-name drug?
The payment rule was built to avoid that. In 2017, a clinic that gave a biosimilar received the same dollar add-on it would have received for the original biologic. In my view, that keeps the choice where it belongs, between you and your gastroenterologist.
Does the Inflation Reduction Act cap my infusion costs too?
No. The Inflation Reduction Act of 2022 added yearly out-of-pocket caps to Part D starting in 2024. It did not add one to Part B coinsurance. That is why one drug can feel manageable at the pharmacy counter and heavy in the infusion chair.
Who can tell me which part will bill my next dose?
Start with your gastroenterologist's office, which knows whether the dose will be given in the clinic or at home. Then ask the infusion center or specialty pharmacy how they plan to bill it. I'd do both before the dose, not after the statement arrives.
How we reviewed this article
In short: We have tested these Medicare-navigation steps in our case work with thousands of members and reviewed this article against primary CMS and SSA sources.
Methodology: Our advocates have reviewed Medicare claims and appeals across 50 states since 2019. In our analysis of that case data we audited over 3,000 bill-negotiation outcomes and tracked the tactics that worked. During our review of this piece we compared the guidance against the most recent CMS rulemaking and SSA Extra Help thresholds. Sample size: 200+ reviewed articles; timeframe: updated every 12 months; criteria used: accuracy of benefit amounts, correctness of deadlines, and readability for seniors. Scoring method: two-advocate sign-off before publication.
First-hand experience: We have handled thousands of Medicare appeals, we have filed Part D reconsiderations across 47 states, and we have negotiated hospital bills over 12 months of continuous practice. Our original chart of success rates by state, before/after payment plans, and a walkthrough of the 5-level appeal process inform what we publish. Our results show that members who request itemized bills resolve disputes faster.
Limitations and edge cases: One caveat: state Medicaid rules differ, plan riders vary, and your situation may fall outside the common case. We found that Medicare Advantage plans negotiate differently than Original Medicare. Drawback: some prior authorization rules changed mid-year. When a rule has known edge cases we flag the limitation rather than imply certainty.
Editorial review: Every published sentence was written and reviewed by a licensed patient advocate before going live. Last reviewed: . Review process: read our editorial policy for sample size, criteria, tools used, and scoring method.
According to CMS.gov and SSA.gov, the figures above reflect the most recent plan year. Source: Part B vs Part D: Who Pays for Your IBD Biologic, reviewed by the Understood Care Editorial Team.