For most of its life, Medicare's drug benefit had a hole in the middle. A person filled prescriptions all spring, then hit a threshold in summer where coverage thinned out dramatically, then, if spending climbed high enough, tumbled into a catastrophic phase where costs eased again. Everyone called it the donut hole, nobody could explain it at a pharmacy counter in under ten minutes, and it turned drug budgeting into a guessing game for millions of retirees. In 2025 that architecture was torn down and replaced with something radically simpler: a hard annual cap on what you pay out of pocket. The cap is genuinely good news. It also moved costs around in ways that deserve a closer look than the headlines gave them.
What replaced the donut hole
Under the redesigned benefit, a standard Part D year has three phases instead of four. You pay your plan's deductible first. After that you pay a share of each covered prescription, typically 25 percent of the cost, and every dollar of that spending counts toward an annual out-of-pocket maximum. When you reach the cap, you pay nothing more at the pharmacy for covered drugs for the rest of the calendar year. For 2025, the first year of the new design, the cap was $2,000, a dramatic drop from the roughly $8,000 in out-of-pocket spending it could previously take to reach catastrophic coverage. The health policy group KFF laid out the numbers in its first look at the 2025 Part D landscape, including the standard deductible for that year: $590.
These figures are indexed, so they drift upward annually. Medicare's own drug coverage cost page shows the current numbers: for 2026 the out-of-pocket cap is $2,100 and no plan may charge a deductible above $615. Whatever year you are reading this, check the current figures rather than the ones from the year the law made news.
What counts toward the cap, and what never will
The cap applies to what you spend at the pharmacy on drugs your plan covers. Specifically, it includes:
- Your annual deductible.
- Copayments on covered prescriptions.
- Coinsurance, the percentage-based cost sharing that applies on many tiers.
Two things stay outside the cap, and both surprise people. Monthly plan premiums do not count and never stop; you keep paying those even after your pharmacy costs hit zero for the year. And drugs your plan does not cover count for nothing, no matter what you spend on them. A medication outside your plan's formulary is invisible to the cap, which is why the formulary review discussed below matters more now than it ever did.
The quiet trade: lower ceilings, higher floors
Insurers did not absorb the cost of capping their sickest members' spending out of generosity; the money had to come from somewhere, and much of it came from the front end of the benefit. Deductibles moved toward the legal maximum across the market, plans that once charged no deductible became scarcer, and many drugs migrated from flat copays to percentage coinsurance. A person taking one expensive specialty medication for cancer or rheumatoid arthritis came out far ahead under the new rules, with thousands of dollars in annual savings. A person taking two cheap generics may well pay more per year than before, through a fatter deductible and higher cost sharing, while never getting anywhere near the cap.
Neither experience is a betrayal; they are the same policy seen from two seats. The redesign shifted the program's protection toward people with catastrophic costs. If you are one of them, the change may be the best financial news of your retirement. If you are healthy, you are now paying a somewhat higher entry price for insurance you hopefully will not need, and the right response is comparison shopping, every single year, rather than loyalty to a plan whose pricing was built for the old rules.
January is the new danger zone
Under the old design, the painful surprise came midyear when a person fell into the gap. Under the new one, the squeeze moved to winter. A deductible near $590 or $615, plus 25 percent coinsurance on expensive drugs, means someone on costly medications can owe hundreds or even a couple thousand dollars in the first weeks of January. The annual total is capped and predictable; the cash-flow spike is real.
The program built a tool for exactly this problem: the Medicare Prescription Payment Plan. Opt in, and instead of paying the pharmacy directly you receive a monthly bill from your plan that spreads your out-of-pocket drug costs across the remaining months of the year, with no interest and no fees. Three things to understand before signing up. It is voluntary and requires contacting your plan; nobody enrolls you automatically. It smooths your spending without reducing it by a dime; the total for the year stays the same. And timing matters: joining in January gives you twelve months of runway, while joining in September crams the same costs into a few large payments. For people whose drug costs cluster early in the year, it can be the difference between a manageable budget line and a raided emergency fund. For people with small, steady costs, it adds little beyond another monthly statement.
The formulary is where your real price is decided
Every plan maintains a formulary, its list of covered drugs sorted into tiers, and formularies are rewritten annually. A drug that cost you a $40 copay last year can move to a tier with 30 percent coinsurance this year, or acquire a prior-authorization hurdle, or vanish from the list entirely. Since uncovered drugs neither count toward the cap nor benefit from it, a single formulary change can quietly restructure your whole year.
The defense takes one evening during open enrollment, which runs from October 15 to December 7. Enter every medication you take, with doses, into the plan finder at Medicare.gov and look at the projected annual cost for each available plan, premiums included. People who do this routinely discover that the cheapest plan for their neighbor is the most expensive one for them, because the entire comparison turns on which specific drugs each plan favors. One more consequence of the cap is worth factoring in: since every plan now has the same out-of-pocket ceiling, paying a premium for a plan with rich early coverage makes less sense for someone who will blow through the cap by March either way. If you know you will hit the maximum, the total you pay is largely premiums plus the cap, so the low-premium plan that covers your drugs often wins.
Does the cap include what a spouse spends?
No. The out-of-pocket maximum is tracked per person, per plan. A married couple each have their own deductible, their own progress toward the cap, and potentially two very different best-plan answers, since each person's medication list drives the math separately.
Where should you go with plan-specific questions?
Your plan's member line can explain your own formulary and cost sharing, and every state runs a free State Health Insurance Assistance Program whose counselors compare plans without earning a commission on your choice. For anything touching treatment itself, such as whether a cheaper covered alternative exists for a drug that moved tiers, that conversation belongs with your doctor or pharmacist, who can often solve at the prescription pad what would otherwise cost hundreds at the counter.
