How Part D Works

• Stand-Alone Prescription Drug Plan (PDP): Works with Original Medicare (Parts A & B).
• Medicare Advantage Drug Plan (MA-PD): Many Advantage (Part C) plans bundle hospital, medical, and drug benefits.
• Plan rules vary: Costs depend on drug tier, pharmacy type, and plan utilization rules (like prior authorization).

Enrollment Snapshot

Part D is offered by Medicare-approved private insurers. Each plan has its own formulary and cost structure (premiums, deductibles, copays/coinsurance). The “best” plan is usually the one that covers your medications at the lowest total annual cost.

Costs You May Pay (vary by plan)

• Monthly Premium: Plan-specific; higher-income enrollees may also have Part D IRMAA.
• Annual Deductible: Some plans have a deductible, others are lower or $0.
• Copays/Coinsurance: Based on drug tier and pharmacy (preferred vs. standard).

What to Check Before You Enroll

• Formulary: Are your medications covered, and on what tier?
• Pharmacies: Is your pharmacy preferred/in-network?
• Utilization rules: Prior authorization, step therapy, quantity limits.
• Annual review: Plans can change premiums, networks, and drug tiers year-to-year.

What Part D Plans Cover

• Prescription drugs (generic & brand) on the plan’s formulary
• Many vaccines and certain insulin products (plan rules apply)

What’s Typically Not Covered

• Most OTC drugs; cosmetic-purpose prescriptions
• Most prescription vitamins/minerals (limited exceptions)

Formularies & Tiers

• Plans commonly use tiers: Tier 1 (low-cost generics) up through Specialty tiers.
• Higher tiers usually mean higher copays/coinsurance.
• If a drug isn’t covered, you may request an exception (plan process applies).