Start with what you actually take

The single best way to pick a Medicare Part D plan is to list every prescription medication you take right now — including the dose and how often — and then check which plans cover each one at what cost. This takes 20 minutes and saves you hundreds of dollars a year. Plans differ wildly in which drugs they cover and how much you pay out of pocket.

Write down the name, strength, and quantity of each medication. If you take a generic version, write that down too; some plans cover the brand name but not the generic, or vice versa. Bring this list with you to every step of the process. You will use it to compare plans on Medicare.gov, and you can also take it to a pharmacist or a Medicare counselor to double-check your findings.

Key Takeaways

  • List every medication you take with the dose and frequency, then use that list to compare plans on Medicare.gov's Plan Finder tool.
  • Part D plans vary by deductible, monthly premium, and which drugs they cover, so the cheapest plan is not always the best for your medications.
  • You can change Part D plans once a year during the Annual Enrollment Period (October 15 to December 7), or when ready if you may have access to for a Special Enrollment Period.
  • State Health Insurance information Programs (SHIP) offer free one-on-one counseling to help you compare plans and understand your costs.
  • Your costs change if you switch pharmacies or if your medications change, so review your plan choice every year.

Use Medicare.gov's Plan Finder to compare actual costs

Go to Medicare.gov and click on "Plan Finder" under the Medicare Plans section. Enter your zip code, then log in with your Medicare account or create one. You will be asked to enter your medications one by one. As you add each drug, the tool shows you which plans cover it and what you will pay — the monthly premium, any deductible, and your copay or coinsurance for that specific medication.

The Plan Finder ranks plans by total estimated yearly cost, which includes your premiums plus what you pay out of pocket for your drugs. This number matters more than the monthly premium alone. A plan with a $15 monthly premium might cost you $2,400 a year if your medications are expensive under that plan, while a $35 monthly premium plan might cost you $1,800 total because it covers your drugs more generously.

Write down the top three to five plans and their total yearly costs. Check whether your pharmacy is in their network — plans have preferred pharmacies where you pay less. If your regular pharmacy is not listed, call the plan to ask whether they will cover your prescriptions there, or switch to a pharmacy in the network.

Understand the four stages of Part D costs

Part D plans charge you in stages as your drug costs add up. First, you pay the deductible — usually between $0 and $545 per year, depending on the plan. Once you have paid that, you move to the initial coverage stage, where you pay a copay or coinsurance (a percentage of the drug cost) for each prescription. Plans vary widely here: one might charge $5 for a generic and $50 for a brand name, while another charges 20 percent of the cost.

If your out-of-pocket costs reach a certain amount — $7,050 in 2024, though this changes yearly — you enter the coverage gap, sometimes called the "donut hole." In the gap, you pay a higher percentage of drug costs. Once your out-of-pocket spending hits the catastrophic threshold (around $10,500 in 2024), you pay a small copay for the rest of the year.

The Plan Finder shows you your costs at each stage for your specific medications. If you take expensive drugs, a plan with no deductible but higher copays might cost less than a plan with a high deductible and lower copays. The only way to know is to run the numbers with your actual medications.

Compare plans side by side before you decide

Once you have narrowed it down to two or three plans, print out or save the detailed cost information from the Plan Finder for each one. Look at the monthly premium, the deductible, the copay amounts for each of your medications, and the total yearly cost. Also check the plan's formulary — the official list of covered drugs — to make sure every medication you take is listed. If a drug is not on the formulary, the plan may not cover it at all, or may require you to try a different drug first.

Check whether the plan requires prior authorization for any of your medications. Prior authorization means the plan asks your doctor to justify why you need that drug before they will pay for it. This adds a delay and extra paperwork, but it does not necessarily mean the plan will deny coverage. If several of your drugs require prior authorization, that plan may be more hassle than it is worth.

Look at the plan's customer service phone number and hours. If you need to call with questions, you want a plan that answers the phone during times you are awake. Some plans offer 24/7 support; others close in the evening or on weekends.

Know when you can change your plan

The Annual Enrollment Period runs from October 15 to December 7 each year. During this window, you can switch to a different Part D plan, and your new coverage starts January 1. If you miss this important date, you are locked into your current plan for the rest of the year unless you may have access to for a Special Enrollment Period.

You may have access to for a Special Enrollment Period if you lose your current coverage (for example, if your employer ends retiree drug coverage), move to a different state, or have a major life event like losing your job. You have 63 days from the event to switch plans. If you think you may have access to, call Medicare at 1-800-MEDICARE to confirm.

Even if you cannot change plans right now, mark your calendar for October 15 next year. Your medications may change, your pharmacy may change, or plan costs may shift. Reviewing your choice once a year takes an hour and can save you hundreds of dollars.

Get free help from a State Health Insurance information Program

Every state has a State Health Insurance information Program (SHIP) that offers free, one-on-one counseling about Medicare plans. A SHIP counselor can walk through your medications with you, help you use the Plan Finder, explain the coverage gap, and answer questions about prior authorization or formularies. They work for your state, not for any insurance company, so they have no reason to steer you toward one plan over another.

To find your state's SHIP, go to Medicare.gov and search for "SHIP" or call 1-800-MEDICARE and ask for the number. You can meet with a counselor in person, by phone, or sometimes by video. Many people find this conversation worth the time, especially if they take multiple medications or have never chosen a Part D plan before.

Review your choice every year, even if you do not switch

Even if you stay in the same plan, your costs may change. Insurance companies adjust their premiums and copays every January. Your pharmacy may leave the plan's network, or new generic versions of your medications may become available at lower cost. Your doctor may prescribe a new medication, or you may stop taking one.

In October, before the Annual Enrollment Period opens, run your current medication list through the Plan Finder again. If your current plan is still the cheapest option, you can stick with it. If a different plan now costs less, you have until December 7 to switch. This yearly check-in is the easiest way to make sure you are not overpaying.

Frequently Asked Questions

What if my medication is not on a plan's formulary?

You can ask your doctor to request a formulary exception, which means asking the plan to cover a drug that is not on their list. The plan may approve it if your doctor explains why that specific medication is medically necessary for you. This takes time, so do not count on it. Instead, ask your doctor whether a similar drug that is on the plan's formulary would work for you.

Do I have to use the pharmacy listed in the plan's network?

Most plans offer lower copays at in-network pharmacies and higher copays at out-of-network pharmacies. You can use an out-of-network pharmacy, but you will pay more. Call the plan before you switch pharmacies to ask what your copay will be at a specific pharmacy, because costs vary by location.

What happens if I miss the December 7 important date?

If you miss the Annual Enrollment Period important date, you stay in your current plan for the rest of the year. You cannot switch until next October 15, unless you may have access to for a Special Enrollment Period due to a life event or loss of coverage. Call Medicare at 1-800-MEDICARE to ask whether your situation qualifies.

Can I change my Part D plan if my medications change?

If your doctor prescribes a new medication that your current plan does not cover well, you may may have access to for a Special Enrollment Period. Call Medicare at 1-800-MEDICARE and explain the situation. They will tell you whether you can switch plans outside the normal enrollment window.

How do I know if a plan requires prior authorization?

The Plan Finder shows you which drugs require prior authorization when you enter your medications. You can also call the plan directly or check their formulary document on their website. Ask your doctor's office whether they have experience with that plan's prior authorization process — some offices handle it quickly, while others find it slow.