Medicare Part D Costs in 2026: The Out-of-Pocket Cap Explained

In 2026, the annual out-of-pocket spending cap for Medicare Part D covered drugs is $2,100. Once your covered drug costs for the year reach that amount, you pay $0 for the rest of the calendar year (Medicare.gov). This cap, created by the Inflation Reduction Act, replaced the older "donut hole" coverage gap system. Actual costs before you hit the cap still vary by plan, pharmacy, and drug, so it is worth comparing prescription prices throughout the year.

How the cap works, step by step

Part D spending for 2026 happens in phases:

1. Deductible phase. You pay out of pocket up to your plan's deductible, capped at a maximum of $615 for 2026 (Medicare.gov). Some plans set a lower deductible or waive it for certain drug tiers.
2. Initial coverage phase. After the deductible, you generally pay 25 percent coinsurance for covered Part D drugs, with your plan and, for certain drugs, the manufacturer covering the rest.
3. Catastrophic phase. Once your covered drug spending for the year reaches the $2,100 out-of-pocket threshold, you pay $0 for covered Part D drugs for the remainder of the calendar year.

As of 2025, there is no longer a separate "initial coverage limit" followed by a donut-hole coverage gap. The initial coverage phase now extends all the way to the annual out-of-pocket threshold, at which point catastrophic coverage begins, according to CMS's contract year 2026 final rule (CMS).

Why the cap rose from $2,000 to $2,100

The Inflation Reduction Act set the initial out-of-pocket cap at $2,000 for 2025, the first year it took effect. For each year after, the law requires CMS to increase the cap by the annual percentage increase in Part D costs, rounded to the nearest $50. Following that formula, CMS finalized the 2026 cap at $2,100 in the CY2026 Rate Announcement and Part D Redesign Program Instructions (CMS). KFF's tracking of the Part D benefit confirms this trajectory and that the cap will likely continue adjusting upward in future years based on drug spending trends (KFF).

What counts toward the cap, and what does not

Your deductible, copays, and coinsurance for drugs on your Part D plan's formulary all count toward the $2,100 threshold. Certain manufacturer discounts and some state pharmaceutical assistance program contributions may also count, depending on the specific program. Monthly premiums never count toward the cap, since the cap applies only to drug costs, not the cost of having the plan itself. Over-the-counter medications, drugs not on your plan's formulary, and most medications covered under Part B rather than Part D (such as many clinic-administered infusions) also do not count.

This distinction matters if you take a drug your plan does not cover well. Paying cash or using a discount card for a non-formulary drug will not move you toward the $2,100 cap, so it is worth checking your plan's formulary tier placement for every medication you take.

The insulin cap works alongside the overall cap

Since January 1, 2023, Medicare Part D has separately limited what beneficiaries pay for insulin. For 2026, the cost-sharing amount for a covered insulin product is the lesser of $35, 25 percent of the drug's Medicare-negotiated maximum fair price, or 25 percent of the plan's negotiated price, with no deductible applied (CMS). Whatever you pay under the insulin cap still counts toward your overall $2,100 out-of-pocket threshold for the year.

Compare prescription prices on BetterBuyRx if you are still in the deductible or initial coverage phase, since a lower cash price at a different pharmacy could sometimes beat your plan's coinsurance amount before you reach catastrophic coverage.

How this interacts with Extra Help

If you qualify for Medicare Extra Help, the federal low-income subsidy, your copays are capped at a much lower level than standard cost sharing, up to $5.10 for generics and $12.65 for brand-name drugs in 2026. Extra Help recipients still benefit from the $2,100 annual cap, but because their copays are already low, they typically reach $0 cost sharing having spent far less than someone paying standard Part D coinsurance.

What to watch for during the year

Because the cap resets every calendar year, it is worth tracking your covered drug spending, especially if you take expensive brand-name or specialty medications. Your Part D plan's Explanation of Benefits statements show your running total toward the $2,100 threshold. If you switch plans mid-year, ask whether your accumulated spending transfers, since this can affect when you reach catastrophic coverage.

Search your medication on BetterBuyRx to see how pharmacy prices compare while you track your progress toward the annual out-of-pocket cap.

The new option to spread costs monthly

Starting in 2025, federal law requires all Part D plans, including Medicare Advantage plans with drug coverage, to offer the Medicare Prescription Payment Plan, which lets enrollees choose to spread out-of-pocket drug costs into monthly payments across the plan year instead of paying larger amounts at the pharmacy counter (CMS). This does not lower your total annual cost or change the $2,100 cap itself; it only changes the timing of when you pay, and CMS notes the option is not necessarily beneficial for every enrollee. It can be worth asking your plan whether this payment option makes sense if you expect to reach the cap through a few expensive fills early in the year.