In This Guide
Prescription drug coverage is one of the most financially impactful parts of Medicare — and 2025 brought the most significant changes to drug cost protections in the program’s 60-year history. Whether you take a handful of generic medications or expensive specialty drugs, understanding how Part D works in 2025 can save you thousands of dollars.
1. How Medicare Part D Works
Original Medicare (Parts A and B) does not cover most outpatient prescription drugs. Part D was added to Medicare in 2006 specifically to cover prescription medications. You can access Part D coverage in two ways:
- Standalone Part D plan: Purchased separately alongside Original Medicare. Premiums average around $39/month in 2025, though plans range widely. You continue to use any doctor who accepts Medicare.
- Medicare Advantage (Part C) plan with drug coverage: Most Medicare Advantage plans bundle Part D coverage into one plan. About 90% of Medicare Advantage enrollees have drug coverage included.
If you are eligible for Medicare and do not enroll in Part D when first eligible, you may face a late enrollment penalty — 1% of the national base beneficiary premium per month for each month you went without coverage. This penalty is permanent and added to your monthly premium for life.
2. The New $2,000 Out-of-Pocket Cap
The single most important Medicare drug coverage change in a generation is now in effect. Starting January 1, 2025, Medicare Part D has a hard $2,100 annual out-of-pocket cap on covered drug costs. This is the result of the Inflation Reduction Act signed in 2022.
In prior years, there was a coverage gap (the “donut hole”) where you could owe 25% of drug costs indefinitely before catastrophic coverage kicked in. The donut hole is now effectively eliminated by the $2,100 cap.
The 2025 Part D cost structure simplified to three phases:
Phase 1: Deductible
You pay 100% of drug costs until you meet your plan’s deductible, which is capped at $615 in 2026. Not all plans charge the maximum deductible—some have lower or $0 deductibles for certain tiers.
Phase 2: Initial Coverage (Cost-Sharing Period)
After your deductible, you pay your plan’s copays or coinsurance for each drug—based on which tier the drug falls in. This continues until your total out-of-pocket spending reaches $2,000.
Phase 3: Catastrophic Coverage — $0 Cost
Once you’ve spent $2,000 out of pocket on covered drugs, Medicare picks up 100% of the cost for covered drugs for the rest of the calendar year. You pay $0 per prescription.
The $2,100 cap is a game-changer for seniors on expensive specialty medications — cancer drugs, rheumatoid arthritis biologics, multiple sclerosis treatments, and similar drugs that previously could push annual drug costs to $10,000 or more.
3. Does Medicare Cover Ozempic and GLP-1 Drugs?
This is one of the most searched Medicare questions of 2024–2025, and the answer has important nuance.
| Drug | Prescribed For Diabetes | Prescribed For Weight Loss Only |
|---|---|---|
| Ozempic (semaglutide injection) | Covered by Part D | NOT covered |
| Rybelsus (semaglutide oral) | Covered by Part D | NOT covered |
| Trulicity (dulaglutide) | Covered by Part D | NOT covered |
| Victoza (liraglutide) | Covered by Part D | NOT covered |
| Wegovy (semaglutide — weight loss dose) | NOT covered | NOT covered |
| Zepbound (tirzepatide — weight loss) | NOT covered | NOT covered |
| Mounjaro (tirzepatide — diabetes) | Covered by Part D | NOT covered |
The key rule: Medicare Part D is prohibited by law from covering drugs prescribed specifically for weight loss. This exclusion dates to the Medicare Modernization Act of 2003 and has not been changed by legislation as of 2026.
If you have type 2 diabetes and your doctor prescribes Ozempic or Mounjaro for blood sugar control, your Part D plan covers it — subject to formulary placement and tier cost-sharing. If you don’t have diabetes and are prescribed Wegovy solely for weight loss, Medicare does not cover it.
There is active legislative discussion about expanding Medicare coverage to include anti-obesity medications, but as of April 2026, no such law has passed.
4. Does Medicare Cover Insulin?
Yes — and with a hard cost cap. Under the Inflation Reduction Act, all Medicare Part D plans must cap cost-sharing for covered insulin products at $35 per month per insulin. This cap applies regardless of which cost phase you are in (including the deductible period).
This $35/month insulin cap applies to insulin administered by injection or inhaled insulin. If you use an insulin pump, the insulin used with the pump is covered under Part B (as durable medical equipment-related supply) and also capped at $35/month.
5. How the Medicare Drug Formulary Works
Every Part D plan has a formulary — a list of covered drugs. Plans are not required to cover every drug, but they must cover at least two drugs in each therapeutic category. If your drug is not on your plan’s formulary, you can:
- Ask your doctor to prescribe a covered alternative in the same drug class
- Request an exception from your plan if there is no covered alternative
- Appeal if your exception is denied
- Switch to a plan that covers your drug at the next open enrollment period
Plans can change their formularies mid-year, but they must give 60 days’ notice for non-protected class drugs. If a drug you take is removed from the formulary, you have the right to a transition supply while you arrange an alternative or appeal.
6. Drug Tiers and What You Pay
Part D plans organize drugs into tiers, with each tier having different cost-sharing. Most plans use a 5-tier structure:
| Tier | Drug Type | Typical Cost-Sharing |
|---|---|---|
| Tier 1 | Preferred generic drugs | $0–$5 copay |
| Tier 2 | Non-preferred generics | $10–$20 copay |
| Tier 3 | Preferred brand-name drugs | $40–$50 copay |
| Tier 4 | Non-preferred brand-name drugs | $100+ copay or 40–50% coinsurance |
| Tier 5 | Specialty drugs (biologics, cancer drugs) | 25–33% coinsurance; counts toward $2,100 cap |
The tier placement of your drug significantly impacts what you pay. A brand-name drug on Tier 3 of one plan might be on Tier 4 of another. Using the Medicare Plan Finder at Medicare.gov to compare plans based on your specific medications is the single most important step you can take during Open Enrollment.
7. How to Lower Your Drug Costs on Medicare
- Use Medicare Plan Finder during Open Enrollment (Oct 15 – Dec 7): Enter every drug you take and compare your total estimated annual drug costs across all plans in your area. The differences can be thousands of dollars per year.
- Ask for generic alternatives: Generics are therapeutically equivalent to brand-name drugs and are typically Tier 1 or Tier 2 — far less expensive.
- Use in-network preferred pharmacies: Most Part D plans have preferred pharmacy networks with lower cost-sharing. Using a non-preferred pharmacy can cost significantly more for the same drug.
- Apply for Extra Help (Low Income Subsidy): If your income and assets are below certain thresholds, you may qualify for Extra Help — a federal program that subsidizes Part D premiums, deductibles, and copays. In 2025, Extra Help can save qualifying individuals $5,000+ per year in drug costs.
- Medicare Prescription Payment Plan: New in 2025, this optional program lets you spread your out-of-pocket drug costs across monthly payments throughout the year rather than paying all at once at the pharmacy. This helps cash flow without increasing total costs.
- Manufacturer patient assistance programs: Major pharmaceutical companies offer copay cards and patient assistance programs that can supplement Part D coverage, though rules for Medicare beneficiaries are more restricted than for commercial insurance.
8. Frequently Asked Questions
Does Medicare cover chemotherapy drugs?
Yes—but through different parts depending on how the drug is administered. IV chemotherapy given in a clinical setting is typically covered under Medicare Part B. Oral chemotherapy pills taken at home are covered under Medicare Part D. Both count toward the $2,100 Part D out-of-pocket cap if billed under Part D.
Does Medicare cover psychiatric medications?
Yes. Antidepressants, antipsychotics, and mood stabilizers are covered under Medicare Part D. These fall into “protected classes” under Part D rules—meaning plans must cover all or substantially all drugs in these therapeutic categories, not just two. This protects access for people with serious mental health conditions.
Does Medicare cover over-the-counter medications?
Generally no. Medicare Part D does not cover over-the-counter medications, even if a doctor recommends them. However, some Medicare Advantage plans offer an annual OTC allowance (a prepaid card worth $25–$200/quarter) that can be used for OTC products at participating retailers.
Does Medicare cover medications given during a hospital stay?
Yes — under Part A. Drugs administered to you during a covered inpatient hospital stay are covered under Part A and do not go through your Part D plan.
Does Medicare cover Eliquis, Xarelto, or other blood thinners?
Yes. Brand-name blood thinners like Eliquis (apixaban) and Xarelto (rivaroxaban) are covered by Part D plans, though they are typically placed in Tier 3 or Tier 4. With the 2025 $2,100 cap, seniors who take these expensive medications will see significant cost relief once they reach the cap.
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This article is for informational purposes only and does not constitute medical or insurance advice. Medicare Part D plans, formularies, and cost-sharing change annually. Always use the Medicare Plan Finder at Medicare.gov to compare plans based on your specific medications. Call 1-800-MEDICARE for personalized guidance.
