The Bill That Doesn't Match the Headline
Ask a retiree in Ohio how her Medicare Part D plan changed this year and she might tell you the premium went down. Ask what she paid at the pharmacy counter in February, and the story flips. The deductible she hit before her plan paid a dime was nearly six times what it was two years ago. Both things are true. Neither one, on its own, explains what actually happened to prescription drug coverage in 2026.
That contradiction is the real story behind the Medicare Part D 2026 changes, and it's a story that mostly hides in the fine print of health insurance company filings and CMS data tables that almost nobody reads outside of Washington policy shops.
The average monthly premium for standalone Part D plans dropped from $39 to $36 this year. Meanwhile, the deductible those same enrollees face climbed toward its legal ceiling. Understanding why both moved in opposite directions tells you almost everything about how the drug benefit actually works now, and what's coming when a federal subsidy program quietly disappears at the end of next year.
56 Million People, Two Very Different Paths to Coverage
Medicare Part D covers prescription drugs for 56 million older adults and people with long-term disabilities. But "Part D" isn't one program with one price tag — it's really two separate markets that happen to share a name.
The first is the standalone Prescription Drug Plan, or PDP, bought by people who have traditional Medicare and need drug coverage added on top. Enrollment in these plans rose to 24.9 million in 2026, up from 23.2 million the year before — the third straight year of growth, driven mostly by employer group plans rather than individual retirees shopping on their own.
The second is the Medicare Advantage Prescription Drug plan, or MA-PD, where drug coverage is bundled into a private Medicare Advantage plan alongside doctor visits and hospital care. This remains the larger of the two markets by far, with 31.4 million enrollees, and it now accounts for 56% of everyone with Part D coverage. That share has been climbing for years, part of the broader shift of Medicare beneficiaries away from the traditional program and into privately managed plans.
Five companies dominate both markets combined. UnitedHealth, Humana, Centene, CVS Health, and Health Care Service Corporation together cover nearly three-fourths of all Part D enrollees — 41.9 million out of 56.3 million people. UnitedHealth alone covers roughly 1 in 5. Centene, less familiar to most consumers than the household names above it, controls more than a third of the standalone PDP market outright.
Why This Surfaced Now
The reason Part D pricing is getting attention this year traces back to a temporary federal program: a premium stabilization demonstration that the Biden administration created in 2024 and the Trump administration renewed for a second year in 2025. It capped how much insurers could raise PDP premiums in a single year, even as underlying costs rose. In late July, CMS announced that the demonstration will end after 2026, with officials arguing insurers now have enough pricing experience to stand on their own.
That decision sets up a very different 2027 for anyone shopping for a standalone drug plan — and it's worth understanding exactly what the stabilization program was quietly doing before its expiration date arrives.
The Premium Went Down. Here's the Catch.
The stabilization demonstration worked almost exactly as designed for one more year. Average PDP premiums fell 7%, from $39 to $36, even while some individual plans raised premiums by as much as $50 a month — the maximum increase the program allowed. Without the cap, that ceiling wouldn't have existed at all.
MA-PD premiums moved the opposite direction, but from a much lower base — up from $7 to $8 a month on average. The gap between the two markets is stark: PDP premiums in 2026 run more than four times higher than MA-PD premiums for the same drug coverage.
That gap isn't a mystery once you see the mechanism behind it. Medicare Advantage insurers receive rebate payments from the federal government for the medical portion of their plans, and they're allowed to use that rebate money to buy down or eliminate the Part D premium entirely. Standalone PDP sponsors have no such rebate pool to draw from, because there's no accompanying medical plan generating one. Rebates to Medicare Advantage plans have roughly tripled since 2015 and now exceed $2,600 per beneficiary per year — money that never touches a hospital bill but quietly subsidizes the drug premium instead.
The result: nearly 8 in 10 MA-PD enrollees without low-income subsidies pay no monthly premium for drug coverage at all, versus roughly 3 in 10 PDP enrollees. Of the people who do pay a PDP premium, the average bill is $57 a month. One plan alone — Wellcare Value Script, priced under $6 a month — accounts for the majority of PDP enrollees paying nothing, having added 1.1 million enrollees in a single year while other national plans lost ground.
The Deductible Nobody Saw Coming
Here is where the story turns. While premiums held roughly steady or fell, deductibles moved sharply in the other direction — and the shift is almost entirely concentrated in Medicare Advantage plans.
In 2024, only 23% of MA-PD enrollees were in a plan that charged any deductible at all for drug coverage. By 2025, that share had jumped to 60%. In 2026, it's 82%. The average MA-PD deductible itself went from $64 in 2024, to $228 in 2025, to $371 in 2026 — a 481% increase in two years.
Standalone PDPs, by contrast, were already charging deductibles close to the legal maximum, so the change there looks smaller on paper but is still real: the average PDP deductible rose from $425 in 2024 to $544 in 2026, with 78% of PDP enrollees now paying the full standard deductible of $615, the maximum allowed this year.
Coinsurance tells a similar story from a different angle. In 2025, only 27% of MA-PD enrollees faced coinsurance — paying a percentage of a drug's price rather than a flat copay — for preferred brand drugs. In 2026, that's 56%. For non-preferred drugs, MA-PD coinsurance exposure rose from 56% to 89% of enrollees in a single year.
None of this happened by accident, and none of it is explained by inflation alone.
What the Redesigned Benefit Actually Changed
To understand why deductibles and coinsurance are absorbing the pressure that used to show up in premiums, you have to look at what the Inflation Reduction Act did to Part D's structure starting in 2025: it eliminated the notorious coverage gap, commonly called the "donut hole," and capped total out-of-pocket drug spending at $2,000 that year, rising to $2,100 in 2026.
That cap is a genuine win for the small share of beneficiaries with very high drug costs — someone on expensive specialty medication no longer faces thousands of dollars in exposure once they exit the gap. But capping the beneficiary's maximum loss didn't make the underlying drug costs disappear. It shifted more of that cost onto plan sponsors, who now cover 65% of costs in the initial coverage phase and 60% in catastrophic coverage, with manufacturers picking up 10% and 20% respectively, and Medicare covering the rest.
Insurers facing that new cost exposure responded the way insurers generally do: by adjusting the parts of the benefit design they still control. They can't touch the out-of-pocket cap — that's fixed in law. They can raise deductibles and shift copays to coinsurance, both of which happened almost immediately after the redesign took effect. The premium stabilization demonstration blocked that same behavior in the PDP premium line specifically, so PDP sponsors that wanted to pass along costs had fewer places to hide it besides the deductible, which is exactly what the data shows.
This is the mechanism most coverage of "Part D changes" skips entirely: the redesign didn't lower costs, it relocated them — compressing the worst-case scenario for the sickest enrollees while quietly raising the starting cost for almost everyone else.
The Three Phases, Explained in Plain Terms
For anyone trying to actually budget around this, Part D in 2026 works in three stages.
During the deductible period, you pay 100% of your drug costs until you hit your plan's deductible — up to $615, though some plans charge less in exchange for a higher premium. Once you clear that threshold, you enter the initial coverage period, where you typically pay 25% of drug costs through copays or coinsurance, your plan covers 65%, and the manufacturer covers the remaining 10%. Total out-of-pocket spending across both phases — deductible, copays, and coinsurance combined — is capped at $2,100 for the year.
Cross that $2,100 threshold and you enter catastrophic coverage, where you pay nothing further for covered medications for the rest of the calendar year. Your plan covers 60% of remaining costs, the manufacturer covers 20%, and Medicare covers 20%.
The practical effect is that the people most exposed to this year's changes aren't the sickest beneficiaries — they're protected by the $2,100 cap either way — but the people whose annual drug spending falls somewhere in the middle: enough to clear a $371 or $615 deductible, not enough to reach catastrophic coverage, and now facing coinsurance instead of a flat copay for the specific drugs they take.
Who Gets Protected, and Who Doesn't
One group is largely insulated from all of this: the 13.6 million people receiving the Part D Low-Income Subsidy, up from 13.1 million in 2025. LIS enrollees don't pay a deductible regardless of what their plan charges, and they receive help with premiums and cost sharing. More than two-thirds of them — 9.3 million people — are enrolled in Medicare Advantage drug plans, and nearly half of all LIS enrollees are in Medicare Advantage Special Needs Plans built specifically for people dually eligible for Medicare and Medicaid.
The 2026 increase in LIS enrollment actually reverses a decline from the year before, one tied less to Part D policy than to Medicaid. When the pandemic-era continuous enrollment protection unwound, many dual-eligible individuals lost Medicaid coverage — and with it, their automatic LIS eligibility, since that subsidy is tied to Medicaid status rather than granted separately. Some of those people have since reapplied or been reinstated, but the episode is a reminder that Part D subsidy stability depends on a completely different bureaucratic system working correctly in the background.
For everyone else, LIS eligibility matters enormously in choosing a plan. Among the ten national PDPs available in 2026, only one — Wellcare Classic — qualifies as a "benchmark" plan in every region, meaning LIS enrollees can join it for zero premium anywhere in the country. Four others are benchmark plans in some but not all regions. Enrollees who pick a non-benchmark plan while receiving LIS end up paying a portion of the premium themselves — something that trips up an estimated 600,000 LIS-eligible PDP enrollees a year, according to CMS enrollment data.
The Insight Hiding in the Numbers
Put the pieces together and a pattern emerges that neither the premium story nor the deductible story tells on its own: Medicare Advantage's zero-premium drug coverage was never really free — it was financed by rebate dollars from the medical side of the plan, and 2026 is the year that financing model started running into the edges of what the redesigned benefit will still allow.
For a decade, MA-PD sponsors could point to a $0 or near-zero drug premium as a selling point while standalone PDPs, unable to draw on medical rebates, carried the visible cost of coverage. That made Medicare Advantage look categorically cheaper for drug coverage, and enrollment data suggests millions of people chose their plan type partly on that basis. But the deductible and coinsurance data for 2026 show the true cost didn't vanish — it simply moved to a part of the bill that isn't advertised in plan comparison tools the way the premium is. An MA-PD enrollee paying $0 a month might now face a $371 deductible and coinsurance on non-preferred drugs that didn't exist two years ago. The headline number stayed attractive. The actual cost of getting sick did not.
This is precisely the dynamic that becomes harder to sustain once the premium stabilization demonstration disappears after 2026. That program only ever protected the PDP side of the market. Its expiration removes one visible cushion, but it doesn't touch the deeper rebate-financed structure propping up MA-PD premiums — which means the 2027 story is less likely to be a uniform price spike and more likely to be a continuation of the same shift already underway: costs moving from the number consumers compare when shopping, to the numbers they discover after they've already enrolled.
What Comes Next: 2027 Bids Are Already In
CMS has already released preliminary numbers for 2027. The national average monthly bid amount — the figure used to calculate government subsidies to plans — will rise to $296.05. The national base beneficiary premium, a benchmark figure used in premium calculations, will be $41.33, up from $36 this year. Under Inflation Reduction Act provisions, annual increases in that base premium are capped at 6% through 2029, which limits how sharply it can rise in any single year even without the stabilization demonstration in place.
CMS Administrator Dr. Mehmet Oz characterized the demonstration's end as a sign of a stabilizing market rather than a benefit cut, stating that premiums would rise by less than $10 for most Medicare recipients in 2027, with some seeing lower premiums. CMS has said it will release final 2027 Medicare Advantage and Part D premium and plan details in September.
Whether that $10 estimate holds once individual insurers finalize their 2027 bids is something only next year's enrollment data will confirm. What the 2026 numbers already show is that premium figures, by themselves, no longer tell the full story of what a Medicare drug plan actually costs — and reading only the premium line, the way most year-over-year comparisons do, is the surest way to miss what's really happening to a household budget.
What Enrollees Can Actually Do With This
The practical takeaway for anyone comparing Part D plans during open enrollment isn't to chase the lowest premium. It's to look at four numbers together: the premium, the deductible, whether the plan uses flat copays or coinsurance for the specific drugs you take, and whether the plan is a benchmark plan if you qualify for the Low-Income Subsidy.
A plan with a $0 premium and a $615 deductible can cost far more over a year than a plan with a modest premium and a low deductible, depending entirely on how many prescriptions someone fills and when in the year they fill them. Someone who takes one generic medication a year experiences Part D completely differently than someone managing three chronic conditions with brand-name drugs — and the redesigned benefit, for all its structural changes, still requires each person to run that same math for their own situation every fall.
That math is unavoidably specific to each household's medications and each plan's formulary tier structure — which is exactly the kind of decision that benefits from sitting down with a plan comparison tool rather than a premium headline.
The Coverage That Doesn't Change, Even When Everything Else Does
Whatever happens to premiums and deductibles in any given year, the $2,100 out-of-pocket cap remains the backstop the Inflation Reduction Act built — the one part of this system that has moved in a single, consistent direction since 2025: down, then held nearly flat. For the small number of beneficiaries with genuinely catastrophic drug costs, that cap is the number that matters most, and it's the one piece of the 2026 changes that isn't a trade-off dressed up as reform.
Frequently Asked Questions
What is the Medicare Part D deductible for 2026?
The maximum standard Part D deductible for 2026 is $615, though many plans charge less. The average deductible varies sharply by plan type: it's $544 for standalone PDPs and $371 for Medicare Advantage drug plans, though the MA-PD figure has risen 481% since 2024, when it averaged just $64.
Why did Medicare Part D premiums go down in 2026 but deductibles go up?
A temporary federal stabilization program capped how much standalone PDP premiums could rise, which pushed average PDP premiums down 7% to $36. But insurers facing higher costs under the redesigned drug benefit shifted more expense into deductibles and coinsurance instead, since those weren't capped the same way.
What is the Medicare Part D out-of-pocket maximum for 2026?
Beneficiaries pay no more than $2,100 out of pocket for covered prescription drugs in 2026. Once that cap is reached, the beneficiary enters catastrophic coverage and pays nothing further for covered medications for the rest of the calendar year.
Is the Medicare Part D premium stabilization program ending?
Yes. CMS announced the demonstration, first created in 2024 and renewed in 2025, will end after 2026. Officials said insurers now have enough experience pricing Part D plans without the program's support, and preliminary 2027 figures show the national base beneficiary premium rising to $41.33.
Do Medicare Advantage drug plans really have no premium?
Nearly 80% of Medicare Advantage enrollees without low-income subsidies pay no monthly premium for drug coverage in 2026. This is possible because Medicare Advantage sponsors can apply rebate payments from Medicare, tied to the medical portion of the plan, toward eliminating the drug premium — an option standalone drug plans don't have.
Who qualifies for the Medicare Part D Low-Income Subsidy?
The Low-Income Subsidy, also called LIS, helps eligible enrollees with premiums and cost sharing based on income and assets. In 2026, 13.6 million people are enrolled in LIS, and those with Medicaid coverage are typically automatically qualified, though losing Medicaid can mean losing LIS unless a person reapplies separately.
