Start with your current medications and pharmacies
The single most useful thing you can do before comparing plans is to write down every medication you take — the exact name, the dose, and how often. Then call or visit your pharmacy and ask which plans they work with. A plan that covers your drugs at your pharmacy is worth far more than a plan with a lower premium that forces you to switch.
Medicare publishes a tool called the Plan Finder on Medicare.gov. You enter your medications there, and it shows you which plans cover each one and what your out-of-pocket cost will be at your pharmacy. This is not a guess — it is the actual price you will pay. Many people skip this step and choose based on the monthly premium alone, then discover in January that their medication costs $200 a month instead of $20.
If you do not have a regular pharmacy yet, or if you are willing to switch, you have more plans to choose from. But if you have a pharmacy you trust and a pharmacist who knows your history, staying there usually saves you money and hassle in the long run.
Key Takeaways
- Enter your exact medications into the Medicare Plan Finder tool before comparing plans, because the out-of-pocket cost for drugs is usually larger than the monthly premium.
- Check whether your current pharmacy is in-network for each plan you are considering, because using an out-of-network pharmacy costs significantly more.
- Part D plans change every year, so you must review your coverage during the annual enrollment period (October 15 to December 7) even if you were happy with your plan last year.
- The coverage gap (also called the donut hole) means you pay more for drugs once you hit a certain spending threshold, so factor this into your total yearly cost estimate.
- If you cannot afford your medications even with Part D coverage, ask your pharmacy about manufacturer discounts and patient information programs before assuming you are stuck.
Understand the cost structure: premiums, deductibles, and the coverage gap
Every Part D plan charges a monthly premium, but that is only the first cost. Most plans also have a deductible — an amount you pay out of pocket before the plan starts helping. Some plans have no deductible. After you meet the deductible, you typically pay a copay (a fixed dollar amount per prescription) or coinsurance (a percentage of the drug cost).
Then comes the coverage gap, sometimes called the donut hole. Once you and your plan have spent a certain amount on drugs in a calendar year, you enter the gap and pay more out of pocket until you reach catastrophic coverage. The exact threshold changes each year. In 2024, the gap begins after combined spending of $5,850. Once you reach $8,550 in out-of-pocket costs, catastrophic coverage kicks in and the plan covers most of the cost again.
This matters most if you take expensive medications or many different drugs. The Plan Finder shows you your estimated total cost for the year, including the gap. Use that number to compare plans, not just the premium. A plan with a $35 monthly premium might cost you $2,400 a year total; a plan with a $50 premium might cost $1,800 total because it covers your specific drugs better.
Compare plans using the official Medicare Plan Finder
Go to Medicare.gov and select "Find Care Providers and Suppliers" or search directly for "Medicare Plan Finder." You will need your Medicare number. Enter your medications (or upload a list from your pharmacy), your pharmacy location, and your zip code. The tool will show you every Part D plan available in your area, ranked by estimated yearly cost.
The results show the monthly premium, the deductible, the copays or coinsurance for each drug tier, and your total estimated out-of-pocket cost for the year. Read the fine print: some plans require prior authorization (the doctor has to get permission before the pharmacy fills the prescription) or step therapy (you have to try a cheaper drug first). These do not change the cost, but they can delay your medication.
You can also call 1-800-MEDICARE and ask a representative to walk you through the Plan Finder over the phone. They cannot tell you which plan to choose, but they can explain how to read the results and answer questions about how the tool works.
Know the enrollment period and plan changes
You can only change Part D plans during the Annual Enrollment Period, which runs from October 15 to December 7 each year. Changes take effect January 1. If you miss this window, you are locked into your current plan for the rest of the year unless you have a may have access to life event (you move, lose other coverage, or have a major change in income).
Plans change every year. The drugs they cover, the copays, the pharmacies in their network, and even whether a plan continues to exist — all of these can shift. A plan that was perfect for you in 2023 might cover your medications differently in 2024. This is why you need to review your coverage every October, even if you were happy last year. Set a calendar reminder.
If you enroll in a plan and realize within the first few weeks that it does not work for you, you have a limited window to switch. Most people get one chance to change plans between January 1 and February 14 if they enrolled during the regular period. After that, you are stuck until October.
Factor in manufacturer discounts and patient information programs
If your medication is expensive even with Part D coverage, the drug manufacturer may offer a discount card or copay information program. These are separate from Medicare and can reduce what you pay at the pharmacy. Ask your doctor or pharmacist whether your medications have these programs, or search the manufacturer's website.
Many drug companies also run patient information programs that provide free or low-cost medication to people who cannot afford it, regardless of income. These programs have their own rules and paperwork, but they exist. If you hit the coverage gap and your costs spike, this is the time to ask your pharmacist about these options.
Some nonprofits, like the Partnership for Prescription information and NeedyMeds, maintain searchable databases of these programs. Your local Area Agency on Aging can also point you toward information in your state.
Decide between standalone Part D and Part D bundled with Part C
You can get Part D coverage two ways: as a standalone plan (called a PDP, or Prescription Drug Plan) that works with Original Medicare, or bundled into a Medicare Advantage plan (Part C), which replaces Original Medicare entirely. If you choose Medicare Advantage, you get drug coverage built in; you do not buy a separate Part D plan.
Standalone Part D plans tend to have lower premiums but higher out-of-pocket costs per drug. Medicare Advantage plans often have $0 premiums but may have smaller pharmacy networks and require you to use in-network doctors. The choice depends on your medications, your doctors, and your pharmacy. Use the Plan Finder to compare both options with your actual drugs and see which costs less overall.
If you have both Medicare and Medicaid (dual may be able to access), or if you receive Extra Help (a federal program that pays Part D costs for low-income people), some plans are designed specifically for you and may have lower costs. Ask about these when you call 1-800-MEDICARE.
Common mistakes to avoid when choosing a plan
The biggest mistake is choosing based on premium alone. A plan with a $15 monthly premium sounds cheaper than one with a $45 premium, but if it does not cover your medications well, you will pay hundreds more per month at the pharmacy. Always use the Plan Finder to see your total yearly cost, not just the premium.
Another common error is assuming your pharmacy is in-network for every plan. Some plans have limited pharmacy networks. If your preferred pharmacy is not in the network, you either switch pharmacies or pay out-of-network rates, which are much higher. Call your pharmacy and ask which plans they accept, or check the plan's website for the pharmacy list before you enroll.
People also forget that plans change every year and assume last year's choice is still the best. Drugs move between tiers, copays increase, and sometimes plans discontinue. Spending 20 minutes in October reviewing your coverage takes less time than spending months next year frustrated with a plan that no longer works for you.
Frequently Asked Questions
What if my doctor prescribes a drug that my Part D plan does not cover?
You can ask your doctor to prescribe a different drug that the plan does cover, or you can request an exception from the plan. The plan may approve the exception if your doctor explains why you need that specific drug. This process takes a few days to a few weeks. If the plan denies the exception, you can appeal. In the meantime, you can pay out of pocket and ask the plan to reimburse you if the appeal succeeds.
Can I change Part D plans if I realize I chose the wrong one in January?
Yes, but only during a limited window. If you enrolled during the regular Annual Enrollment Period (October 15 to December 7), you can change plans once between January 1 and February 14. After February 14, you are locked in until the next October unless you have a may have access to life event like moving or losing other coverage.
Do I have to choose a Part D plan if I take no medications?
You do not have to enroll in Part D right now if you do not take regular medications. However, if you go without Part D coverage and later decide you need it, Medicare charges a penalty for each month you were not enrolled. The penalty is added to your premium permanently. If you think you might need medications in the future, it is usually cheaper to enroll now even if you do not use it.
What happens to my Part D coverage if I move to a different state?
Your current plan may not be available in your new state. You can change plans without waiting for October if you move. Contact your current plan and Medicare to report the move, and use the Plan Finder with your new zip code to see what plans are available where you are moving. You have 60 days after you move to enroll in a new plan.
How do I know if I may have access to for Extra Help with Part D costs?
Extra Help is a federal program for people with limited income and resources. You can explore through Social Security, Medicare.gov, or your local Medicaid office. If you may have access to, the program pays your premium, deductible, and most of your copays. Call 1-800-MEDICARE to ask whether you might may have access to, or visit the Social Security website to start an process.