Core Insurance Solutions
    By Core Insurance SolutionsNovember 5, 2026
    Medicare Drug Tiers: How Part D Tiers Set Your Copay

    Medicare Drug Tiers: How Part D Tiers Set Your Copay

    Medicare drug tiers are the cost levels a Part D plan uses to sort the drugs on its formulary (its list of covered drugs). A drug on a lower tier generally costs you less than a drug on a higher tier, and each plan decides for itself which drug goes where. So the same prescription can cost very different amounts under two plans. Below you will find what each tier usually means, what typical costs look like, how the coverage stages interact with tiers, and how to check your own medications.

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    TL;DR

    Table of Contents

    What Medicare drug tiers are

    Every Part D plan, whether a stand-alone drug plan or a Medicare Advantage plan with drug coverage, publishes a formulary. Medicare.gov explains that plans use tiers to help lower costs, and that each plan can divide its tiers in different ways. A plan must include at least two drugs in the most commonly prescribed categories and classes, but it chooses which ones.

    Medicare.gov gives these example tiers:

    Tier What it usually holds Your share
    Tier 1 Most generic drugs Lowest copayment
    Tier 2 Preferred brand-name drugs Medium copayment
    Tier 3 Non-preferred brand-name drugs Higher copayment
    Specialty tier Very high-cost drugs Highest cost share

    This is an example, not a rule. A plan may use three, four, five or more tiers, and the labels differ. One plan’s Tier 2 may be generics while another’s is preferred brands. Always read the tier descriptions in the specific plan’s documents rather than assuming a number means the same thing everywhere.

    What each tier typically costs in 2027

    Cost sharing comes in two forms: a flat copayment (for example $8) or coinsurance, a percentage of the drug’s price. Lower tiers lean toward copays. Higher tiers lean toward coinsurance.

    KFF’s analysis of 2027 Part D plans reports median standard cost sharing across plans:

    Drug category Stand-alone drug plans Medicare Advantage drug plans
    Preferred generics $4 $0
    Other generics $20 $5
    Preferred brands 25% coinsurance Varies by plan
    Specialty drugs 25% coinsurance 26% coinsurance

    These are medians. Your plan could charge less or more, and your actual cost depends on the stage of coverage you are in (more on that below). Treat the table as a way to understand the shape of the tiers, then confirm the exact amounts in the plan you are considering.

    Why a higher tier is not always a higher bill

    A drug’s tier is only one piece. Your deductible, whether you are still in the initial coverage stage, the pharmacy you use and the day supply you choose all change what you pay at the counter. Some plans, for example, do not apply the deductible to their lowest tiers. Aetna’s Medicare guidance, for instance, notes that the deductible may not apply to Tier 1 and Tier 2 drugs in some plans and points you to your Evidence of Coverage to confirm. That is why two people on the same tier can pay different amounts in January.

    How tiers fit with the Part D coverage stages

    Tiers decide your share per prescription. The coverage stages decide when that share applies.

    1. Deductible. Per Medicare.gov, no plan may have a deductible above $615 in 2026 or $700 in 2027, and some plans have none. In this stage you may pay the full negotiated price of drugs the deductible applies to.
    2. Initial coverage. You pay your tier’s copay or coinsurance. Medicare.gov says that for generic and brand-name drugs you pay 25% coinsurance until your out-of-pocket spending reaches $2,100 in 2026 or $2,400 in 2027.
    3. Catastrophic coverage. Once you reach that limit, you automatically move into catastrophic coverage for the rest of the calendar year.

    If you want the full story of that cap, our guide to the Medicare donut hole and the $2,100 cap walks through it step by step.

    Why the same drug lands on different tiers

    Plans negotiate prices with drug manufacturers and then decide where each drug goes. UnitedHealthcare explains that when a plan negotiates a lower price, it can place the drug in a lower tier and pass savings on, which is how one drug ends up on Tier 2 in one formulary and Tier 3 in another.

    This matters for popular brand-name medicines such as blood thinners. We would not tell you a single tier for any brand-name drug, because it depends on the plan and the plan year. What we can say is that you should look the drug up plan by plan, by name and by dose.

    Some protections exist. Per Medicare.gov, all Part D plans must include most drugs in certain protected classes, including cancer drugs, HIV/AIDS drugs, antidepressants, antipsychotics, anticonvulsants and immunosuppressants for organ transplants. A drug being on the formulary still does not tell you its tier, so the lookup is still necessary.

    Mid-year changes and generics

    Tiers are not frozen. Medicare.gov notes that your coinsurance may rise when a manufacturer raises a drug’s price. It also notes that your cost may go up if a generic version arrives, the plan moves the brand to a higher tier and you stay on the brand. If your doctor says the brand is medically necessary, ask about a tiering exception. Our tiering exception toolkit explains the prescriber form and timing.

    How to check a drug’s tier before you enroll

    The most useful habit is to check by name, not by category. Here is a simple process.

    1. List everything you take. Include name, strength, how often and how many days’ supply you usually fill.
    2. Find each plan’s formulary. Carriers post a drug list and a drug search tool. As an example of how these work, Aetna says you can enter your ZIP code, find your plan, and download the formulary to see the tier, any limits or rules, and whether mail order is available.
    3. Note the restrictions. Beyond tier, look for prior authorization, step therapy and quantity limits. They can matter as much as price.
    4. Compare pharmacies. Preferred pharmacies often charge less. Mail order may lower costs for maintenance drugs, and our guide to setting up a mail order pharmacy covers the steps.
    5. Read the Evidence of Coverage. It is the plan’s binding document for what you will pay.

    If you are curious about newer injectable medicines, coverage differs widely by plan and by the reason a drug is prescribed. A general overview of Wegovy insurance coverage shows the kinds of questions to ask before you assume anything is covered, and your plan’s formulary has the final word.

    Perspective: why we start with your medication list

    Most people choose a Medicare drug plan by looking at the monthly premium. We think that gets the order backwards. The premium is one line. Your tiers, deductible and pharmacy network decide most of what you spend over the year.

    When we sit down with a client in Lakeland or anywhere in Polk County, we begin with the medications they take and the doctors they see. Our Holistic Health Needs Assessment is built to look at the whole picture, and then we compare plans from the carriers we work with, drug by drug.

    We also look at the plan again every year. Formularies and tiers can change, and a plan that fit last year may not fit this year. Our annual Rate Watch and policy audit exists for exactly that reason.

    Our service comes at no direct cost to you. Carriers compensate us when you enroll, and our job is to help you understand your options so you can choose with confidence.

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    The late enrollment penalty and tiers

    Tiers are not the only thing that raises Part D costs. If you go 63 days or more in a row without Part D or other creditable drug coverage after your initial enrollment period ends, you may owe a late enrollment penalty. According to a 2026 Part D Evidence of Coverage, the penalty is 1% for every full month without creditable coverage, multiplied by the national base beneficiary premium ($38.99 for 2026) and rounded to the nearest 10 cents. It is added to your monthly premium for as long as you have Part D.

    A worked example: 20 full months without creditable coverage is 20%, and 20% of $38.99 is about $7.80 a month, added to your premium. MedPAC’s March 2026 report estimates that about 5% of beneficiaries pay the penalty, with an average of about $15 a month. It also notes that creditable retiree coverage can protect you from the Part D penalty.

    To estimate your own figure, try our Part D penalty calculator.

    The late enrollment penalty and tiers

    How many people are choosing between plan types

    You have two main routes to drug coverage. KFF reports that in 2025, 54.8 million people were enrolled in Part D: 58% in Medicare Advantage plans with drug coverage and 42% in stand-alone drug plans. If you pair Original Medicare with a Medigap policy, you would add a stand-alone drug plan. Our page on Medigap versus Medicare Advantage in Florida compares how each route handles drug coverage and other costs.

    KFF also reports that in 2025 most stand-alone plans include a deductible, averaging $491, so the deductible is worth comparing alongside the tiers.

    How many people are choosing between plan types

    Get help comparing plans in Polk County

    If you are turning 65, retiring, or helping a parent sort out drug coverage, the fastest way to see how your medications are tiered is to compare plans with your actual list in hand. We review your prescriptions, compare the plans available to you from the carriers we work with, and look for ways to lower your drug costs. You can see the full range on our services page.

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    If you live in Lakeland, Plant City, Winter Haven, Bartow or nearby, see our Part D plans in Lakeland, FL or start from our home page. We do not offer every plan available in your area. Any information we provide is limited to the plans we do offer in your area. Please contact Medicare.gov or 1-800-MEDICARE (TTY 1-877-486-2048) to get information on all of your options.

    FAQ

    What tier is Eliquis?

    It depends on your plan. Each plan decides where a brand-name drug sits, and the same drug can be on different tiers in different formularies. Look up the drug by name and dose in the formulary of each plan you are considering, or ask us to run the comparison.

    What Medicare plan covers prescription drugs?

    Medicare Part D covers prescription drugs. You can get it through a stand-alone drug plan added to Original Medicare, or through a Medicare Advantage plan that includes drug coverage. Either way, the plan’s formulary and tiers determine what you pay.

    What is the late enrollment penalty for Part D?

    It is an extra amount added to your monthly premium if you go 63 days or more in a row without Part D or other creditable drug coverage after you are first eligible. It is 1% of the national base beneficiary premium for each full month, and it applies for as long as you have Part D.

    Can I ask my plan to lower the tier of a drug I need?

    Yes, you can request a tiering exception. Your prescriber generally has to support the request by explaining why a lower-cost alternative would not work for you. Our tiering exception guide covers the form and the timeline.

    Sources

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