For years, Medicare patients taking Humira or adalimumab biosimilars faced a brutal cost structure: a coverage gap (the "donut hole") that could push annual out-of-pocket costs into the thousands, with no copay cards available to soften the blow (federal law prohibits them for Medicare patients).
That changed in 2026. A provision of the Inflation Reduction Act instituted a $2,100 annual out-of-pocket cap for Medicare Part D beneficiaries — meaning once you've paid $2,100 in covered drug costs in a calendar year, your plan covers 100% of prescription costs for the rest of the year.
For patients on adalimumab, this is a significant development. Here's how to make the most of it.
How the $2,100 Cap Works
The cap applies to covered out-of-pocket costs under your Medicare Part D plan — deductibles, copays, and coinsurance all count toward the $2,100 limit. Once you hit the cap, your cost-sharing drops to $0 for covered drugs for the remainder of the calendar year.
A few important details:
- The cap resets every January 1
- Only costs you actually pay out of pocket count — insurance payments and manufacturer subsidies don't count toward the cap
- The drug must be on your plan's formulary (covered) to count
For adalimumab, which is typically a specialty-tier drug, the math means most patients will hit the $2,100 cap relatively quickly in the year — sometimes in the first two or three fills — and then pay nothing for the rest of the year.
The Biosimilar Pricing Layer
Adalimumab biosimilars are generally priced lower than brand Humira, and many Medicare Part D plans have placed biosimilars on more favorable tiers. Depending on your plan:
- Biosimilars may have a lower coinsurance rate than brand Humira (e.g., 25% vs. 33%)
- Getting to the $2,100 cap faster with a lower-priced biosimilar means paying less before the cap kicks in
- Some plans cover biosimilars at preferred tiers with fixed copays rather than percentage coinsurance
Run your current plan's formulary search (at medicare.gov/plan-compare or by calling your plan) to compare:
- Which adalimumab products are covered
- What tier each is on
- What your specific coinsurance/copay rate is
A lower-tier biosimilar will get you to the $2,100 cap faster — and the cap is the same regardless of which covered adalimumab you use.
Extra Help: If $2,100 Is Still Too Much
The $2,100 cap is the new standard for Medicare Part D, but for lower-income beneficiaries, there's an additional federal program: Extra Help (also called the Low Income Subsidy or LIS).
Extra Help significantly reduces or eliminates Part D premiums, deductibles, and copays for qualifying patients. In 2026:
- Full Extra Help: Copays as low as $4.50 for generic drugs and $11.20 for brand/specialty drugs per fill
- Partial Extra Help: Reduces costs to a sliding-scale amount based on income
Eligibility is based on income and assets:
- Individual income below ~$22,590/year (2026 threshold)
- Individual assets below ~$17,220 (excluding your home and car)
If you meet these thresholds, Extra Help can reduce your adalimumab costs to roughly $11–$45 per fill, far below the standard Part D cap path.
Apply through: SSA.gov/extrahelp or call 1-800-772-1213 (Social Security). You can also be auto-enrolled if you have Medicaid.
What About Medicare Advantage Plans?
If you have a Medicare Advantage (Part C) plan with prescription drug coverage, the same $2,100 out-of-pocket cap applies — but the specific formulary, tier placement, and coinsurance rates vary by plan.
Medicare Advantage plans have more flexibility in how they structure drug coverage, which means adalimumab costs can vary significantly between plans. During Medicare open enrollment (October 15 – December 7), compare plans specifically on the adalimumab/biosimilar cost at the formulary tool level, not just the premium.
The Patient Assistance Question
Can Medicare patients access manufacturer patient assistance programs (PAPs) for adalimumab? The rules are complex:
- Manufacturer copay cards are prohibited for Medicare patients (federal law)
- Manufacturer PAPs (free drug programs) are a different category — some manufacturers do accept Medicare patients if other eligibility criteria (income, lack of adequate coverage) are met
- The key question is whether your Medicare Part D plan actually covers the adalimumab product. If it doesn't, you may have a financial need argument that qualifies you for a PAP
Contact the specific biosimilar manufacturer's patient assistance program and be specific about your Medicare situation when you call.
ClariMeds can evaluate your full eligibility picture — Medicare Part D coverage, Extra Help, and applicable PAPs — in one place.
Check your eligibility — about 5 minutes
This article contains general Medicare program information. Coverage details, income thresholds, and plan terms change annually. Verify current information at medicare.gov or by contacting your Part D plan.