Medicare Part D Drug Plans Cover
Medicare Drug Coverage

What Medicare Part D Drug Plans Cover

Medicare Part D helps cover the cost of prescription medications. Plans are offered by private insurers approved by Medicare and must follow federal rules.

2025: $2,000 cap on covered Part D out-of-pocket $35/month insulin cap (see update)

Formularies (List of Covered Drugs)

  • Every Part D plan has a formulary (its covered drug list).
  • Plans must include a broad mix of drugs in each therapeutic class.
  • Formularies can change yearly — review during Open Enrollment.

Tiers of Coverage

Tier 1: Low-cost generics
Tier 2: Preferred brand-name drugs
Tier 3: Non-preferred brand-name drugs
Specialty: High-cost/specialty medications

Higher tiers generally mean higher copays or coinsurance.

Generic & Brand-Name Drugs

  • Generics work the same as brands and usually cost less.
  • Brand-name drugs are covered but often at higher cost-sharing.

What’s Not Covered

  • Over-the-counter (OTC) medications
  • Cosmetic/lifestyle drugs (e.g., hair growth, weight loss)
  • Most prescription vitamins/minerals (limited exceptions)

Tip: Coverage and costs vary by plan. Check that your prescriptions are covered and at which tier before enrolling. Review annually during Open Enrollment.

Important Update: Part D plans cap covered insulin at $35 for a one-month supply (effective 2023 and ongoing). For insulin used via a traditional pump under Part B, the cap also applies.