Saving by Switching Your Medicare Part D Plan
It can pay to switch your Medicare Part D plan. Medicare Part D plans—the prescription drug plans offered by Medicare—can change from year to year, sometimes dramatically. Premiums, deductibles, copays, pharmacy networks, and even which medications are covered can all vary. As a result, a plan that worked well to cover your prescription drug costs in 2025 may not be the most cost-effective choice in 2026.
During Medicare’s fall open enrollment period (October 15 through December 7 every year), enrollees have the opportunity to review their coverage and, if needed, switch to a plan that better fits their prescriptions and budget. For some retirees, this annual review can mean saving hundreds of dollars in the coming year.
Why Part D?
Navigating Medicare can be complex. Original Medicare includes Part A (hospital insurance) and Part B (medical insurance). While Parts A and B cover a wide range of services, they leave important gaps: notably, prescription drugs are not included.
To fill those gaps, retirees generally choose between two approaches:
Medicare Advantage combines Parts A and B, often with drug coverage, and may include extras like dental or vision. Premiums are typically low, but out-of-pocket costs can add up if you need extensive care, and coverage is usually limited to provider networks.
Medigap + Part D: With original Medicare, many choose a Medigap supplemental policy plus a standalone Part D drug plan. This approach has higher monthly premiums but offers more predictable costs and broad access to providers.
Option 2 above requires that you decide which Medigap policy and which Part D policy will suit your needs.
Selecting a Part D Plan
Because insurers offer different levels of coverage, it often pays to shop around for a Part D plan. The Medicare Plan Finder tool at medicare.gov makes this process easier. You can log in to save your information, or you can explore options without logging in.
You’ll start by entering your zip code.
Next, add all medications you are currently taking. You’ll need to know the names of your medications, dosage, and frequency of use. This is the most important factor when selecting the right plan because your costs can vary widely depending on your medications.
Next, you will add the names of pharmacies that you prefer. Part D plans often have preferred pharmacies where co-pays may be lower.
The tool will then bring you to a list of available drug plans and provide the monthly plan premium, the total deductible, and the estimated total cost for the year for all prescriptions and premiums.
You can click into the “Plan Details” and explore how projected costs are calculated. Are your drugs covered? How much do monthly premiums vary? What should you expect to pay out-of-pocket from month to month? Make sure you’re not choosing a plan based solely on the cost of the monthly premiums. The all-in cost with co-pays is more informative.
Once you’ve decided which plan looks most suitable for your needs, you can enroll right from the website. You may need to provide your Medicare number, information about your other health coverage, and dates that the changes are to take effect. For those switching during the fall open enrollment, changes take effect on January 1, 2026.
Why Go Through the Hassle?
If you’ve already enrolled, it may be tempting to stick with your current Part D plan. But costs and coverage shift annually.
Drug formularies can change from year to year, meaning that any plan might add or drop a medication from its list, move it to a higher or lower-cost tier, or add new restrictions (like prior authorization). Plans can also raise or lower monthly premiums, deductibles, and co-pays. This means that your projected costs can change even if your medications are the same.
New plans enter the marketplace and old plans leave every year. Reviewing your options ensures you don’t get stuck in an outdated or overpriced plan.
Finally, if you are taking any new prescriptions, check your options. You may find a new plan that covers your new medications at a lower overall cost.
People I’ve worked with to explore their options can often find cost savings, sometimes as high as $600 per year, depending on their circumstances and medications. According to data from KFF, nearly half of beneficiaries who switched Part D plans saw a decrease of at least 5 percent the following year.
Even if your prescriptions stay the same, reviewing your plan during open enrollment ensures your medications remain covered and may save you hundreds of dollars. A quick check on Medicare’s website can make a real difference in your costs next year.
This article originally appeared in The Berkshire Eagle and the Squared Away blog at The Center for Retirement Research at Boston College.