Medicare Drug Coverage: Check If Your Medication Is Covered

How to Check If Medicare Covers Your Medication

Every Medicare Part D plan and Medicare Advantage plan with prescription drug coverage maintains a formulary — a complete list of the medications the plan covers. Formularies vary from plan to plan, so a drug covered by one plan may not be covered by another, or may be placed on a different cost tier.

To check whether your specific medications are covered, you can review the plan's formulary on their website, call the plan's member services line, or use the Medicare Plan Finder at Medicare.gov. Our drug search tool lets you enter your medications and compare coverage across multiple plans in your area at once.

What to Look For

• Whether your drug is listed on the formulary at all
• Which tier the drug is placed on (this determines your cost)
• Whether any restrictions apply (prior authorization, step therapy, quantity limits)
• Whether a generic or preferred alternative is available at a lower tier

Understanding Formulary Tiers

Medicare Part D formularies organize medications into tiers that determine how much you pay out of pocket. Lower tiers have lower costs, while higher tiers have higher copays or coinsurance percentages. Most plans use a five-tier structure, though some plans may use fewer tiers.

Standard Five-Tier Structure

• Tier 1 — Preferred Generic: The lowest-cost tier, typically $0 to $15 per prescription. These are widely used generic medications that the plan considers first-line treatments.
• Tier 2 — Generic: Non-preferred generics with slightly higher copays, usually $5 to $25 per prescription.
• Tier 3 — Preferred Brand: Brand-name medications that the plan has negotiated favorable pricing on. Copays typically range from $30 to $50.
• Tier 4 — Non-Preferred Brand: Brand-name drugs that cost the plan more, often with copays of $80 to $100 or coinsurance of 30% to 40%.
• Tier 5 — Specialty: High-cost medications for complex conditions like cancer, rheumatoid arthritis, or multiple sclerosis. Costs are typically 25% to 33% coinsurance, though the annual out-of-pocket cap now limits total exposure.

Plans can place the same drug on different tiers, so comparing formularies is essential. A medication on Tier 4 with one plan might be on Tier 3 with another, saving you hundreds of dollars per year.

Prior Authorization and Step Therapy

Some medications on a plan's formulary come with utilization management restrictions. These are tools insurance plans use to control costs and ensure appropriate use of medications. The two most common restrictions are prior authorization and step therapy.

Prior Authorization (PA)

Prior authorization requires your doctor to get approval from the plan before the plan will cover a medication. Your doctor submits clinical documentation explaining why the drug is medically necessary. The plan reviews the request and either approves or denies it, usually within 72 hours for standard requests or 24 hours for expedited requests.

Step Therapy

Step therapy requires you to try one or more lower-cost medications before the plan will cover a more expensive drug. For example, the plan might require you to try a generic blood pressure medication before approving a brand-name alternative. If the first-step drug does not work or causes side effects, your doctor can request an exception.

Quantity Limits

Some medications have quantity limits that restrict how much of the drug you can get per fill or per month. This is common for controlled substances and high-cost medications. If your prescribed dosage exceeds the quantity limit, your doctor can request an exception from the plan.

What to Do If Your Request Is Denied

• Ask your doctor about a covered therapeutic alternative
• Request a formulary exception with supporting clinical documentation
• File an appeal if the exception is denied (you have 60 days)
• Contact your State Health Insurance Assistance Program (SHIP) for free help

The Coverage Gap (Donut Hole)

The Medicare Part D coverage gap, commonly known as the donut hole, is a phase of drug coverage where your cost-sharing temporarily changes. You enter the coverage gap after you and your plan have spent a combined amount on covered drugs that reaches the initial coverage limit set by CMS each year.

How the Coverage Gap Works in 2026

Thanks to the Inflation Reduction Act, the coverage gap has been eliminated. Starting in 2025, Medicare Part D includes an annual cap on out-of-pocket spending for prescription drugs — $2,000 in 2025, rising to $2,100 for 2026. Once you reach this cap, you enter catastrophic coverage and pay nothing for covered drugs for the rest of the year.

This is a major change from previous years when beneficiaries could face thousands of dollars in out-of-pocket costs during the coverage gap. The new cap applies to all Part D plans and Medicare Advantage plans with drug coverage.

Key Points

• The $2,100 annual out-of-pocket cap includes deductibles, copays, and coinsurance
• Plan premiums do not count toward the cap
• Once you reach the cap, your plan covers 100% of covered drug costs
• Plans may offer a monthly payment option to spread out-of-pocket costs evenly across the year
• The cap applies to all covered Part D drugs, including specialty medications

The $35 Monthly Insulin Cap

The Inflation Reduction Act capped the cost of insulin at $35 per month per covered insulin product for all Medicare beneficiaries enrolled in Part D or a Medicare Advantage plan with drug coverage. This cap took effect in 2023 and is now a permanent feature of Medicare prescription drug coverage.

What the Insulin Cap Covers

• All plan-covered insulin products, including vials, pens, and biosimilars
• Applies during the deductible phase, initial coverage, and the coverage gap
• No prior authorization can be required for covered insulin at the capped price
• Applies regardless of which tier insulin is placed on in the formulary

If you use insulin, this cap can save you hundreds of dollars per year. Before the cap, some Medicare beneficiaries paid $100 or more per month for insulin, particularly during the coverage gap. Check your plan's formulary to see which insulin products are covered.

Insulin and Plan Selection

While all Part D plans must cap insulin at $35 per month, the specific insulin products on each plan's formulary may vary. If you use a specific brand or type of insulin, verify that your plan covers it before enrolling. Our drug search tool can help you compare insulin coverage across plans in your area.

How to Switch Plans If Your Drug Is Not Covered

Discovering that your medication is not covered by your current plan is frustrating, but you have options. The right approach depends on your situation and the time of year. Here is what you can do if your drug is missing from your plan's formulary or placed on a tier that is too expensive.

Immediate Options (Any Time of Year)

• Ask about alternatives:Your doctor may be able to prescribe a therapeutically equivalent medication that is on your plan's formulary at a lower tier.
• Request a formulary exception: Your doctor can submit a request to your plan asking them to cover the drug or move it to a lower tier based on medical necessity.
• Use manufacturer assistance: Many drug manufacturers offer copay assistance cards or patient assistance programs for Medicare beneficiaries.

Switching Plans During Enrollment Periods

If you want to switch to a plan that covers your medication, you can make changes during these enrollment windows.

• Annual Enrollment Period (AEP): October 15 through December 7. You can switch to any Medicare Advantage or Part D plan available in your area. Changes take effect January 1.
• Medicare Advantage Open Enrollment (OEP): January 1 through March 31. You can switch Medicare Advantage plans or return to Original Medicare with a standalone Part D plan. Changes take effect the first of the following month.
• Special Enrollment Period (SEP): If you have a qualifying event, you can switch plans outside of standard enrollment windows.

Before switching, use our drug coverage tool or Medicare.gov's plan finder to verify that the new plan covers all of your medications at tiers and costs you are comfortable with. A licensed Medicare agent can help you compare options at no cost.

Paying for Your Drugs: The Medicare Prescription Payment Plan

If your covered medications carry high out-of-pocket costs, the Medicare Prescription Payment Plan can make them easier to budget for. Offered on every Part D and Medicare Advantage drug plan since 2025, this program lets you pay your share of prescription costs in monthly installments across the year instead of all at once at the pharmacy counter. There is no fee to join and no interest.

The Prescription Payment Plan does not change what your drugs cost or which drugs your plan covers — your formulary, tiers, and yearly out-of-pocket cap all stay the same. It simply spreads the bill into monthly payments, which tends to help most when you face a large cost early in the year. Signing up is voluntary and free, and you can leave at any time. Contact your plan or a licensed Sidebar advisor to see whether it fits your situation.

Compare Drug Coverage Across Medicare Plans

Checking drug coverage one plan at a time is tedious. Our drug search tool lets you enter all of your current prescriptions and instantly see which Medicare plans in your area cover them, what tier each drug is placed on, and what your estimated out-of-pocket costs would be under each plan.

How It Works

1. Enter the names of the medications you currently take
2. Provide your ZIP code to find plans in your area
3. Review side-by-side plan comparisons showing coverage and estimated costs
4. Connect with a licensed agent if you need help choosing or enrolling

Whether you are enrolling in Medicare for the first time, reviewing your coverage during AEP, or considering a switch, checking your drug coverage is the most important step in choosing the right plan. Prescription drug costs are the number one reason Medicare beneficiaries switch plans each year.