Rising prescription drug costs have forced many older Americans to ration medication or skip doses altogether, but a federal cap taking effect in the new year is meant to put a hard ceiling on that expense. Starting in 2027, once a Medicare Part D enrollee’s true out-of-pocket spending on covered drugs reaches $2,400 for the calendar year, the enrollee’s plan picks up the entire remaining cost of covered prescriptions through December 31. The number is one of the first pieces of the 2027 Medicare drug benefit that the Centers for Medicare & Medicaid Services has finalized, and it continues a phase-in that began with the Inflation Reduction Act’s overhaul of the Part D benefit. For a retiree managing several brand-name prescriptions for conditions such as diabetes, heart disease, or cancer, that fixed ceiling can be the difference between predictable annual drug spending and costs that once climbed into the tens of thousands of dollars.
The $2,400 Catastrophic Threshold: What Counts and What It Covers
Under the redesigned Part D benefit, the $2,400 figure represents the annual out-of-pocket threshold that triggers what CMS calls the catastrophic phase of drug coverage. Once a beneficiary’s true out-of-pocket costs, known as TrOOP, reach that amount in a given calendar year, cost-sharing on covered Part D drugs drops to zero for the remainder of the year. TrOOP counts the annual deductible along with any coinsurance or copayments paid during the initial coverage phase, plus manufacturer discounts provided on brand-name drugs while a beneficiary is in that phase. It does not count monthly plan premiums, which continue regardless of how much a beneficiary spends on medication that year, and it does not count spending on drugs that are not on a plan’s covered formulary.
Medicare’s official guidance on Part D drug coverage confirms the same three-phase structure applies to nearly every standalone Part D plan and Medicare Advantage plan with drug coverage, running from the deductible phase through the initial coverage phase to the catastrophic phase where the cap takes effect. Beneficiaries taking high-cost specialty medications, including many cancer and autoimmune drugs that can list for tens of thousands of dollars a year, are the ones most likely to reach the $2,400 threshold well before the calendar year ends.
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The Road to the Cap: A $700 Deductible, Then 25% Coinsurance
Reaching the $2,400 ceiling in 2027 starts with a standard deductible of $700, up from $615 in 2026, under CMS’s finalized 2027 payment policies. A beneficiary pays that amount in full before a plan begins sharing costs, unless the plan chooses to waive or reduce the deductible for certain drug tiers. After the deductible is met, most enrollees move into the initial coverage phase, where they typically pay roughly 25% of the cost of covered drugs while the plan, and for certain brand-name drugs the manufacturer, cover the rest until total out-of-pocket spending hits the $2,400 mark.
CMS finalized those figures in its 2027 Medicare Advantage and Part D Rate Announcement, released in April 2026, confirming both the higher deductible and the $2,400 out-of-pocket threshold as part of the annual indexing required under the Inflation Reduction Act. Plans must build their 2027 benefit designs, including any supplemental coverage in the deductible or initial phases, around those finalized figures before Medicare’s fall open enrollment period.
A Cap That Has Climbed Fast Since the Inflation Reduction Act Redesign
The $2,400 figure is the third annual increase to the out-of-pocket cap since the Inflation Reduction Act eliminated Part D’s old coverage gap, commonly called the donut hole, and created a hard ceiling for the first time. The threshold began at $2,000 in 2025, rose to $2,100 in 2026, and now reaches $2,400 for 2027 under a statutory formula that indexes the cap to growth in per-capita Part D spending nationwide, meaning the ceiling can rise faster than general inflation in years when nationwide drug spending accelerates.
The same release set the 2027 Part D base beneficiary premium at $41.33 and the national average monthly bid amount at $296.05, figures CMS uses to calculate what individual plans can charge; actual premiums vary plan by plan and can run well above or below that base amount depending on a plan’s benefit design and region. A beneficiary’s premium is separate from the $2,400 out-of-pocket cap and continues to be billed monthly no matter how much has been spent on prescriptions.
Spreading the Cost: The Medicare Prescription Payment Plan Option
Beneficiaries who would rather not pay the deductible and coinsurance in full at the pharmacy counter have another tool available heading into 2027: the Medicare Prescription Payment Plan, sometimes called M3P. The option, created under the same Inflation Reduction Act redesign, lets any Part D enrollee elect to have out-of-pocket drug costs billed monthly by the plan instead of paid upfront at the pharmacy, spreading the expense across the remaining months of the calendar year rather than absorbing a large bill in January when the deductible resets.
Medicare’s program page for the payment plan option makes clear that it does not reduce the total amount owed on the path to the $2,400 catastrophic threshold, but it can ease the cash-flow strain for beneficiaries living on fixed Social Security or pension income. Enrollment in the payment plan is voluntary and handled directly through a beneficiary’s existing Part D or Medicare Advantage drug plan, with no separate application to a government agency required, and a beneficiary can opt in or drop out from one plan year to the next.
This article was produced with AI assistance and reviewed by The Financial Wire editorial team.
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Warren Cohen is a finance writer based in Phoenix, Arizona, covering personal finance topics including credit, banking, and beginner investing. He earned his degree in business administration from Arizona State University and began his career working in consumer finance, where he gained direct experience with lending and credit systems. He now writes for personal finance websites and fintech platforms, focusing on clear, practical content that helps readers make informed financial decisions.
