Best Prescription Drug Plans for Seniors on Medicare
The right Part D plan depends on your medication list. Here is how to compare plans using your own drugs and pharmacy, and what the yearly out-of-pocket cap changes.
No Medicare drug plan is best for everyone. The right plan for you covers your medications on low tiers, works with a pharmacy you use, and has the lowest total cost for the year once you add the premium, deductible and copays. That differs for every drug list, so a plan that suits a neighbor may cost you more. Use Medicare's Plan Finder to compare, not a ranked list.
Each stand-alone Part D plan and each Medicare Advantage plan with drug coverage sets its own formulary, pharmacy network and prices. A plan that works well for someone on three generic blood pressure drugs can be a poor choice for someone on one expensive specialty drug. This site does not sell insurance or rank carriers. Below is what to check and where.
Why "best" depends on your drug list
Plans sort covered drugs into tiers, from preferred generics on the lowest tier to non-preferred brands and specialty drugs on the highest. Your cost changes sharply by tier: a few dollars on the lowest, and 25% coinsurance or more on the highest.
Two plans with similar premiums can put the same drug on different tiers. Here is a made-up comparison for one brand-name drug taken all year:
| Plan A | Plan B | |
|---|---|---|
| Monthly premium | $15 | $45 |
| Your drug's copay | $100 a month (non-preferred tier) | $40 a month (preferred tier) |
| Premiums for the year | $180 | $540 |
| Copays for the year | $1,200 | $480 |
| Total for the year | $1,380 | $1,020 |
The plan with the higher premium costs $360 less over the year. Deductibles are left out to keep the example simple.
How to compare with Medicare Plan Finder
- Go to medicare.gov/plan-compare. It is free and you do not have to sign up.
- Enter each medication with its exact name, dose and how often you take it. Copy them from the bottles.
- Add the pharmacies you use.
- Sort the results by "lowest drug + premium cost." That figure is your estimated total for the year.
- Open the top two or three plans and check each drug for restrictions: prior authorization, step therapy and quantity limits.
Repeat this every fall, even if you like your plan. Formularies and prices change each January.
What to check: Formulary
Does the plan cover each of your drugs, and on which tier? A drug that is not on the formulary may not be covered without an exception request.
What to check: Pharmacy network
Preferred pharmacies often have lower copays than standard network pharmacies. Mail order can lower costs for maintenance drugs.
What to check: Total annual cost
Add the premium, the deductible (up to $615 in 2026, $700 in 2027) and expected copays. A low premium with poor coverage of your drugs often costs more overall.
What to check: Star rating
Medicare rates plans from 1 to 5 stars on quality and customer service. The rating does not show whether your drugs are covered at a good price.
Star ratings and their limits
Every Medicare Advantage and Part D plan gets a yearly rating from 1 to 5 stars, based on measures such as member satisfaction, customer service and how well the plan manages chronic conditions. If a 5-star plan is available in your area, you can switch into it once during the year outside the regular enrollment period.
Use the rating as one factor. It says nothing about the price of your own drugs, so check the formulary first.
The out-of-pocket cap
The Part D "donut hole" ended in 2025. Your out-of-pocket spending on covered drugs is now capped each year: $2,100 in 2026 and $2,400 in 2027. After you reach the cap, covered prescriptions cost $0 for the rest of the year.
- If your drug costs are high, you will reach the cap under almost any plan that covers your drugs. Compare premiums, and confirm that every drug is on the formulary, because spending on drugs the plan does not cover does not count toward the cap.
- If your drug costs are modest, you will not come near the cap. The tier and copay for your regular drugs matter most.
If large bills early in the year are hard to manage, the Medicare Prescription Payment Plan spreads them over monthly payments. The Part D Out-of-Pocket Calculator shows when you would reach the cap.
Medicare Advantage plans with drug coverage
Many Medicare Advantage plans include drug coverage. If you are open to either route, compare stand-alone Part D plans (with Original Medicare) and Medicare Advantage drug plans side by side. The same out-of-pocket cap for drugs applies to both. For the wider trade-offs, see our Medicare Advantage vs Original Medicare comparison and, if you are pairing Original Medicare with a supplement, the Medigap Plan Comparison Tool.
If cost is still a barrier
- Extra Help. The federal Low-Income Subsidy. For 2026 it is generally available with income up to about $23,940 a year for one person ($32,460 for a couple) and limited resources. It can remove your premium and deductible and cap copays at a few dollars. People with Medicaid, SSI or a Medicare Savings Program get it automatically. Check with our Extra Help calculator.
- State Pharmaceutical Assistance Programs. A small number of states still run one. See the state program finder.
- Manufacturer Patient Assistance Programs. Drug makers run these themselves. See the patient assistance finder.
- Ask about alternatives. Your doctor or pharmacist may know of a generic or a drug on a lower tier that would work for you.
When you can make a change
Changes to Part D and Medicare Advantage plans are generally made during the Annual Enrollment Period, October 15 through December 7, and take effect January 1. Outside that window you need a Special Enrollment Period, for example after moving, losing other coverage or qualifying for Extra Help, or the one-time switch to a 5-star plan. Our Annual Enrollment Period guide has this year's dates and figures.
Frequently Asked Questions
What is the best Medicare Part D drug plan?
No single plan is best for everyone. The right plan covers your medications on low tiers, includes a pharmacy you can use, and has the lowest total yearly cost (premium, deductible and copays) for your drug list.
How do I compare Part D plans for my specific medications?
Use Medicare's Plan Finder at medicare.gov/plan-compare. Enter your exact medications, doses and pharmacy, and it estimates your yearly cost under each plan available to you.
What are Part D formulary tiers?
Formularies group covered drugs into tiers, from preferred generics on the lowest tier to non-preferred brands and specialty drugs on the highest. Copays and coinsurance are much lower on lower tiers, so the same drug can cost very different amounts in different plans.
Do star ratings actually matter when choosing a plan?
They are a useful measure of customer service and plan quality, on a scale of 1 to 5 stars. They do not show whether a plan covers your drugs at a good price, so check the formulary as well.
When can I switch Part D plans?
During the Annual Enrollment Period, October 15 through December 7, with changes effective January 1. Some people qualify for a Special Enrollment Period at other times, including a one-time switch into a 5-star plan where one is available.
This article is for general educational purposes and reflects Medicare Part D rules and figures as of October 2026. It is not insurance advice and does not recommend or endorse any insurance carrier or plan. For a comparison based on your own medications, use medicare.gov's Plan Finder or contact your State Health Insurance Assistance Program (SHIP) for free help.