What is Part D?
Part D is Medicare prescription drug coverage. It is offered through private plans approved by Medicare. Drug coverage may come through a stand-alone Part D plan or be included in many Medicare Advantage plans.
What should you compare?
- Your medications and how they are covered on the plan formulary.
- Your preferred pharmacy and whether it is in-network or preferred.
- Estimated annual drug costs—not just the premium.
- Prior authorization, quantity limits or step therapy requirements.
Creditable coverage matters
If you have prescription coverage from another source, review whether it is considered creditable before deciding to delay Part D enrollment.
Official resources
You can compare current drug plan information at Medicare.gov Plan Compare.
2027 Part D costs
For 2027, a Medicare drug plan may have a deductible of up to $700. The annual out-of-pocket threshold for covered Part D drugs is $2,400. Your actual premium, deductible, copays, coinsurance, formulary and pharmacy network depend on the plan you choose.
CMS projects the average monthly premium for stand-alone Part D plans at about $36 in 2027. This is a national average, not a quote or guarantee for any individual plan. The 2027 national base beneficiary premium used in the Part D premium and late-enrollment-penalty calculation is $41.33.
People who qualify for Extra Help have a $0 plan premium and $0 deductible in 2027, with copays up to $5.80 for generics and $14.40 for brand-name drugs at participating pharmacies.
2027 Part D Star Ratings are available
CMS released the 2027 Medicare Advantage and Part D Star Ratings on October 8, 2026. Weighted by enrollment, approximately 22% of stand-alone Part D plan enrollees are currently in contracts that will have four or more stars in 2027, up from about 2% in 2026.
CMS also added new medication-safety measures for 2027, including measures addressing concurrent use of opioids and benzodiazepines and the use of multiple anticholinergic medications in older adults. Star Ratings are one factor to consider along with your medications, pharmacies, formulary, total expected costs and plan rules.