Original Medicare doesn't cover most outpatient prescription drugs. Medicare Part D is the program that does - private drug plans, approved and regulated by Medicare, that cover the medications you fill at the pharmacy. And Part D has changed more in the last two years than in the previous fifteen: there is now a hard annual cap on what you pay out of pocket for covered drugs, the old "donut hole" coverage gap is gone, and insulin costs are capped. If your understanding of Part D was formed a few years ago, it deserves a fresh look.
Medicare Part D Prescription Drug Coverage
Two Ways to Get Part D
- A standalone Prescription Drug Plan (PDP) paired with Original Medicare - usually alongside a Medicare Supplement plan.
- Built into a Medicare Advantage plan (MA-PD).Most Medicare Advantage plans include drug coverage; if you're on one, your drug coverage is part of the plan and you don't (and generally can't) enroll in a separate PDP.
What Part D Costs in 2026
- Monthly premium: Varies by plan. The average standalone Part D premium in 2026 is about $34.50 per month , with plans in most markets ranging from under $10 to over $100. Higher-income enrollees pay an additional income-related amount (IRMAA) on top of the plan premium.
- Deductible: Plans may charge up to $615 in 2026 before coverage begins; many plans charge less, and some apply no deductible to lower drug tiers.
- Copays/coinsurance: Set by each plan's tier structure - generic tiers typically cost the least, preferred brands more, specialty drugs the most.
- The annual out-of-pocket cap: In 2026, once your out-of-pocket spending on covered Part D drugs reaches $2,100 , you pay $0 for covered prescriptions for the rest of the year. The cap counts your deductible, copays, and coinsurance (not your premiums).
The Donut Hole Is Gone - Here's What Replaced It
For years, Part D had a dreaded "coverage gap": after your drug costs hit a threshold, you paid a much larger share until catastrophic coverage kicked in. Beneficiaries on expensive medications could spend $8,000 or more in a year with no ceiling at all.
That structure no longer exists. Under the Inflation Reduction Act, Part D introduced a true annual out-of-pocket cap - $2,000 when it launched in 2025, indexed to $2,100 for 2026 . For people managing conditions with high-cost specialty medications, this is one of the most significant improvements in Medicare's history: your worst-case pharmacy year is now a known, capped number.
Two related protections worth knowing:
- Insulin is capped at $35 per month for covered insulin products on every Part D plan - no deductible applies.
- The Medicare Prescription Payment Plan lets you spread your out-of-pocket drug costs across the year in monthly installments instead of paying large sums at the pharmacy counter in the early months. You opt in through your plan.
The Formulary: Why the "Cheapest" Plan Can Be the Most Expensive
Every Part D plan has a formulary - its list of covered drugs, organized into cost tiers. Formularies differ plan to plan, and this is where most Part D mistakes happen: people pick the plan with the lowest premium, then discover a medication they take is on a high tier, not covered at all, or subject to restrictions like:
- Prior authorization- the plan must approve the drug before it's covered.
- Step therapy- you must try a lower-cost alternative first.
- Quantity limits- caps on how much is covered per fill.
The only reliable way to compare Part D plans is to run your exact medication list, dosages, and preferred pharmacy through each plan's pricing. A plan with a $50 premium can easily beat a $12 plan once real drug costs are counted. This comparison is precisely what our licensed agents do, at no cost to you.
Pharmacy Networks Matter Too
Part D plans contract with pharmacy networks, and many designate preferred pharmacies where your copays are lowest. The same plan can price the same drug differently at the pharmacy across the street. If you have a pharmacy you're loyal to - or you use mail order - that belongs in the comparison.
The Late Enrollment Penalty: Don't Learn This One the Hard Way
Part D is voluntary, but delaying it can cost you permanently. If you go 63 or more consecutive days without Part D or other creditable drug coverage (such as employer coverage that's at least as good as Part D) after your Initial Enrollment Period ends, Medicare adds a late enrollment penalty to your premium - roughly 1% of the national base premium for every month you went without coverage - and you pay that penalty for as long as you have Part D. Even if you take no medications today, a low-cost Part D plan is often worth it purely to avoid a lifelong penalty. Details on timing windows: Medicare Enrollment Periods.
Help Paying for Part D: Extra Help / LIS
The federal Extra Help program (also called the Low-Income Subsidy) pays some or all of Part D premiums and deductibles and sharply reduces copays for people with limited income and resources. Many people who qualify never apply. If money is tight, ask us about Extra Help and about Dual-Eligible Special Needs Plans - we screen for both as part of any consultation.
Reviewing Your Plan Every Year Isn't Optional
Plans change their formularies, tiers, premiums, and pharmacy networks every January. The plan that fit you perfectly two years ago may treat your medications very differently next year. Each fall you'll receive an Annual Notice of Change from your plan - and the Annual Enrollment Period (October 15 – December 7) is your window to compare and switch for the following year. A ten-minute review with an agent every fall is the cheapest insurance there is.
MegaCare's licensed agents run your medication list against the Part D and Medicare Advantage drug coverage available in your area and handle enrollment - free of charge.
Call 888-918-6920 TTY: 711, Mon-Fri 9am-6pm EST
Frequently Asked Questions
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Is Part D mandatory?
No, but going without creditable drug coverage for 63+ days after becoming eligible triggers a permanent late enrollment penalty when you do enroll.
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What counts toward the $2,100 cap?
Your deductible, copays, and coinsurance for drugs covered by your plan. Premiums and drugs not on your plan's formulary don't count.
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Can I have a standalone Part D plan with Medicare Advantage?
Generally no - if your Medicare Advantage plan includes drug coverage, enrolling in a standalone PDP can disenroll you from your MA plan. (Limited exceptions exist for certain plan types like some PFFS plans.)
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What if my drug isn't on the formulary?
You and your prescriber can request a formulary exception, switch to a covered alternative, or choose a different plan at your next enrollment window.
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Does Part D cover drugs administered in a doctor's office?
Drugs administered to you in clinical settings (like infusions) are typically covered under Part B, not Part D. Part D covers the prescriptions you fill yourself.
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When can I change my Part D plan?
During the Annual Enrollment Period (October 15 - December 7), during the Medicare Advantage Open Enrollment Period if you're switching MA plans, or with a Special Enrollment Period if you qualify - for example, if you move or lose other coverage.