Definition. A Prescription Drug Plan (PDP) is a stand-alone Medicare Part D plan that covers prescription drugs only. You add it to Original Medicare, with or without a Medigap policy. It's different from an MA-PD, where drug coverage is built into a Medicare Advantage plan.
What it means
You might join a PDP if:
- You have Original Medicare and want drug coverage.
- You have Original Medicare and a Medigap policy (Medigap doesn't cover drugs).
- You're in a Medicare Advantage plan type that allows a separate drug plan, such as some Private Fee-for-Service plans without drug coverage or a Medical Savings Account plan.
PDPs are offered by private companies that contract with Medicare. Each has its own formulary, pharmacy network, premium and cost-sharing, and all follow Part D rules such as the yearly out-of-pocket cap ($2,100 in 2026).
In Oregon
For 2027, CMS lists 8 stand-alone Part D plans in Oregon from 4 companies, the same in every county because Oregon is in Part D region 30 with Washington. Plans change formularies and costs every year, so check yours during Open Enrollment, which runs through December 7. You can see drug plans for your ZIP code on PlanMatch or use Medicare.gov's Plan Finder.
Sources
- Medicare.gov — What Medicare drug coverage (Part D) covers
- Medicare.gov — Joining a health or drug plan
- CMS — Part D public use file record layout (PDP regions) (PDF)
Frequently asked questions
Can I have a PDP and a Medicare Advantage plan?
Usually not. Joining a PDP while you're in a Medicare Advantage HMO or PPO disenrolls you from the Medicare Advantage plan. Exceptions include some Private Fee-for-Service plans without drug coverage and Medical Savings Account plans.
When can I join or switch PDPs?
When you first get Medicare, during Open Enrollment (October 15 to December 7, for coverage starting January 1), or with a Special Enrollment Period, such as when you move or lose other drug coverage.
Are stand-alone drug plans the same everywhere in Oregon?
Yes. Stand-alone plans are offered by Part D region, and Oregon and Washington share region 30, so the same PDPs are available in every Oregon county. Pharmacy networks still differ by plan.
Medicare in your Oregon county
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