What the Medicare Part D Drug Cap Means at the Pharmacy

Two Changes That Took Effect in January

Two significant changes to Medicare prescription drug coverage went into
effect on January 1, 2026, and they are working together to reduce costs
for some of the highest-need enrollees in the program. The first is an
annual cap on out-of-pocket prescription drug spending. The second is
the debut of lower negotiated prices on ten high-cost medications.
Understanding how both work - and who benefits - requires a look at the
structure of Medicare Part D.

The 2,100-dollar cap and the drug price negotiations both stem from the
Inflation Reduction Act of 2022. They represent the most significant
structural changes to Medicare Part D in the program’s history.

How the Out-of-Pocket Cap Works

In 2024, Medicare Part D enrollees had to spend 8,000 dollars out of
pocket on covered medications before entering catastrophic coverage -
the phase where a plan pays 100 percent of costs for the rest of the
year. That threshold dropped to 2,000 dollars in 2025 and has been
adjusted to 2,100 dollars in 2026, with annual inflation-based
adjustments going forward.

According to GoodRx, once an enrollee’s cumulative out-of-pocket
spending on covered Part D drugs reaches 2,100 dollars in 2026, their
plan pays the full cost of covered medications for the remainder of the
calendar year. The cap applies automatically - no additional enrollment
is required - and it applies to standalone Part D plans and Medicare
Advantage plans that include prescription drug coverage.

The donut hole coverage gap, which previously created unpredictable
spikes in drug costs for many enrollees, was permanently eliminated at
the end of 2024. The 2026 benefit structure now runs from a deductible
phase directly to an initial coverage phase, then into catastrophic
coverage once the 2,100-dollar threshold is reached.

The 10 Negotiated Drugs

For the first time in Medicare’s history, the program has directly
negotiated prices with pharmaceutical manufacturers. Ten Part D drugs -
selected based on their high cost and widespread use - now carry what
CMS calls Maximum Fair Prices, which took effect January 1, 2026.

According to AARP, the drugs cover a range of conditions including heart
disease, diabetes, autoimmune disorders, and cancer. The list includes
Eliquis, Jardiance, and Xarelto, among others. AARP’s analysis of
stand-alone Part D plans found that average out-of-pocket costs for the
56 plans reviewed would be less than 100 dollars per month for seven of
the ten negotiated drugs - compared to only two of the ten in 2025.
Out-of-pocket costs for the ten drugs are projected to fall by an
average of more than 50 percent for eligible beneficiaries enrolled in
original Medicare.

CMS estimates that approximately 9 million Medicare Part D enrollees use
one or more of the ten negotiated drugs and could see savings. Total
projected savings across all Part D enrollees in 2026 from the
negotiated prices alone amount to 1.5 billion dollars.

Who Benefits Most

The combination of the 2,100-dollar cap and lower negotiated drug prices
is most impactful for enrollees with chronic conditions who take
high-cost brand-name medications. A beneficiary taking Eliquis for
atrial fibrillation or Jardiance for diabetes, for example, may hit the
annual cap earlier in the year - meaning their out-of-pocket costs stop
accumulating much sooner than they would have under prior rules.

For enrollees who take less expensive generic medications and rarely
approach the old catastrophic threshold, the direct financial impact of
the new cap may be modest. The change matters most to the subset of
enrollees for whom annual drug costs were previously open-ended and
unpredictable.

What the Cap Does Not Cover

There are important limits to what the 2,100-dollar cap applies to. It
covers only drugs on a plan’s formulary. Medications that are not on a
plan’s approved drug list do not count toward the cap - meaning
out-of-pocket costs for those drugs could continue to accumulate
separately. Monthly Part D premiums also do not count toward the cap,
nor do drugs covered under Medicare Part B rather than Part D, such as
certain physician-administered infusions.

AARP and Medicare planners have consistently noted that the annual open
enrollment period - which runs each fall from October 15 through
December 7 - remains the most important window for enrollees to compare
plans based on their specific drug list, since formularies, deductibles,
and cost-sharing structures can vary significantly from one plan to
another. A plan with a lower monthly premium may not be the most
cost-effective choice once a beneficiary’s specific medications are
factored in.

A Structural Shift, Not a Complete Fix

The 2026 changes represent a meaningful structural improvement to
Medicare’s drug benefit - particularly for the millions of Americans who
take high-cost medications for serious chronic conditions. The cap
provides a ceiling that simply did not exist before 2025. The negotiated
prices reduce costs for specific high-use drugs at a scale that
individual price comparison could not achieve.

For many Medicare enrollees, the experience at the pharmacy counter is
already different this year than it was two years ago. For others, the
changes are still working their way through plan formularies and
coverage structures in ways that may take additional time to become
visible.

References: 3 Big Medicare Prescription Drug Changes Coming in 2026 | Medicare Part D Out-of-Pocket Limit is $2,100 in 2026