Part D Tier Levels: What a Tier Means for What You Pay and How to Ask for a Tier Exception

You look up a drug in your Part D plan and see Tier 3. It is easy to read that as a price. It is not a price. A tier is a group a plan puts a drug in. Your cost is the copay or share the plan sets for that tier and that drug. This guide shows how tiers work and how to ask for a tier exception. See our medications hub and the drug pages that link to this topic for drug-by-drug facts.

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How a drug list is built

Each Part D plan has a drug list. The list is split into tiers, often numbered from low to high. Lower tiers tend to hold low cost generic drugs. Higher tiers tend to hold brand drugs and special drugs that cost the plan more.

Plans in the same town can put the same drug on a unlike tier. So Tier 2 in one plan can be Tier 3 in the next. That is why you check your own plan list each fall, and check the drug by name and dose.

The tier tells you where to look for the cost. The plan cost line for that drug tells you the amount.

• Tier 1 often holds the lowest cost generics, in many plans.
• Mid tiers often hold a mix of generics and brand drugs.
• High tiers often hold special drugs with a share cost, not a flat copay.
• Some drugs need prior approval, a step drug first, or a limit on amount.

What you pay, step by step in the year

Your year has cost steps. First you may pay a deductible. The maximum standard deductible in 2026 is $615 (Ledger A9). Some plans have a lower deductible or none for some tiers. Your plan summary states yours.

Next you pay copays or a share for each drug until your own costs reach the cap. In 2026 that cap is $2,100, then you pay $0 for covered drugs for the rest of the year (Ledger A10).

Insulin has its own cap. For Part D covered insulin, you pay no more than $35 for a month supply per product (Ledger A12). That cap holds even in the deductible step.

For 2027, the standard amounts change. The deductible is $700 and the cap is $2,400 from January 1, 2027 (Ledger A17 and A18). Label those as next year amounts if you plan ahead this fall. They do not rule your 2026 costs.

Our total yearly cost guide for Part D shows how to add premium, deductible, and drug costs in one count. Our Part D in 2027 guide covers the next year changes. One medication guide from the November 3 group is linked from drug pages in this section. A tier is not a price on those pages either: the coverage note there points back to the plan cost.

What a tier exception is

A tier exception is a request to pay the lower tier cost for a drug your plan puts on a higher tier. You ask when your doctor says the lower tier drugs for your health issue will not work for you, or would harm you.

It is not the same as a request to cover a drug that is not on the list at all. That is a different request. A tier exception keeps the drug covered, but at a lower cost tier.

You or your doctor can make the request. The plan will ask the doctor for a note that says why the lower tier drugs will not work. Plans must act in set time frames. Your plan letter will state the outcome and your right to appeal if they say no.

Who pays for what

• Original Medicare does not pay for most outpatient drugs on its own. Part D plans pay for covered drugs.
• Your Part D plan pays its share of covered drug costs after your deductible and copays, under its tier rules.
• You pay the premium, the deductible up to $615 at most for the standard benefit in 2026 (Ledger A9), and your tier costs until the $2,100 cap (Ledger A10).
• Medicaid and Extra Help can lower drug costs for people who qualify.
• Private pay covers drugs the plan does not cover and costs before a tier exception is granted.

Sample situation

Frank is 70. His blood pressure drug moved to Tier 3 in his plan this year. He first reads the tier as the price and worries the drug will cost three times more. He then checks the plan cost line for that drug and dose. The cost is a set copay, higher than last year but not a set tier price. His total drug costs for the year still sit below the $2,100 cap for 2026 (Ledger A10). Frank asks his doctor if a Tier 2 drug would work as well. His doctor says no, based on a past side effect. Frank files a tier exception with the doctor note. The plan grants it, and he pays the Tier 2 cost for that drug for the rest of the year.

How to check a drug before you join or switch

Slot 9 in this group covers the Medicare Prescription Payment Plan, which spreads Part D costs across the year.

• Write the drug name, dose, and how often you take it, exactly as on the label.
• Look it up in the plan list for the year you are joining, not last year.
• Note the tier, the cost for that tier, and any prior approval or step rule.
• Add the cost across a full year, with the deductible, to get your true total.
• If the cost shocks you, ask about a tier exception or a like drug on a lower tier.

Sources

• https://www.medicare.gov/health-drug-plans/part-d/basics/costs