Prescription Drugs
Drug Tier
Quick answer
Drug tiers group medications by cost. Lower tiers (preferred generics, generics) have the lowest copays; higher tiers (preferred brand, non-preferred brand, specialty) cost more.
Plain-English definition
Most plans use a 5-tier structure but the exact layout varies.
Why it matters
The same drug can be Tier 2 on one plan and Tier 4 on another.
A simple example
Your generic statin is Tier 1 with a $0 copay at a preferred pharmacy.
Common mistakes & misconceptions
Related terms
Formulary
A formulary is the official list of prescription drugs a Medicare Part D or Medicare Advantage plan covers, organized by tier. Every plan has its own formulary, and the same drug can be a different tier from one plan to another.
Tier Exception
A tier exception is a formal request for your plan to charge the lower-tier copay for a drug currently placed on a higher tier.
Preferred Pharmacy
A preferred pharmacy has a special contract with your Part D or Medicare Advantage plan that gives you lower copays on covered drugs compared to a standard network pharmacy.
Frequently asked questions
Can I get a lower tier?+
You can request a Tier Exception with your doctor's support.
Sources & references
📚 Where this information comes from
- Medicare.gov — official U.S. government site for people with Medicare ↗Primary source for benefits, enrollment periods, and plan comparison.
- CMS.gov — Centers for Medicare & Medicaid Services ↗Federal rulemaking, program updates, and official guidance.
- Social Security Administration — Medicare enrollment & premiums ↗Enrollment, premium withholding, and IRMAA determinations.
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Medicare Caddies is an independent insurance agency. We are not affiliated with, endorsed by, or connected to the U.S. government, the federal Medicare program, or the Centers for Medicare & Medicaid Services (CMS). We help compare Medicare Advantage plans from the insurance companies we represent, and we don't offer every plan available in your area.