Understanding Part D Drug Plans
Stand-alone prescription coverage in plain English — who needs it, the penalty to avoid, and how to pick well.
Who Needs a Stand-Alone Drug Plan?
Original Medicare does not cover most prescription drugs — that's what Part D exists for. You'd typically add a stand-alone Part D plan if you:
- Keep Original Medicare by itself, or
- Pair Original Medicare with a Medicare Supplement (Supplements never include drug coverage).
If you choose a Medicare Advantage plan, drug coverage is usually built in — most people on those plans don't add a separate Part D plan.
Even If You Take No Medications: the Penalty
Here's the part that surprises people. If you go without drug coverage (or other "creditable" coverage, like from an employer) for more than 63 days after becoming eligible, Medicare adds a late enrollment penalty to your premium when you eventually join: about 1% extra for every month you waited — permanently.
That's why many healthy people carry a modest drug plan even with an empty medicine cabinet: it protects the future, and it avoids a penalty that never goes away.
Good News: There's Now a Yearly Cap
In 2026, your out-of-pocket prescription costs under Part D are capped at $2,100 for the year. Hit the cap, and your plan pays 100% of covered medications for the rest of the year. There's also a no-cost option to spread your drug costs into even monthly payments — ask about it if large pharmacy bills at the start of the year are a strain.
How to Compare Plans (It's Not About the Premium)
The cheapest premium is often not the cheapest plan. What actually determines your yearly cost:
- The drug list ("formulary"): is every one of your medications covered, and on what tier?
- Your pharmacy: plans have "preferred" pharmacies where the same drug costs less — is yours one of them?
- The math across the whole year: premium + deductible + copays for your exact medications.
This is exactly the comparison we run for you — your medication list, against every plan available in your area, at no cost to you.
Two Things to Remember Every Year
- Plans change annually. A drug that's covered this year can move tiers or drop off next year. Review during the October 15 – December 7 window.
- Moving changes your options. Drug plans are regional — relocate, and you'll likely choose from a new lineup. See our moving guides for the deadlines.