Part D is the name of Medicare's prescription drug coverage. It's insurance that helps people pay for prescription drugs. It is available to everyone who has Medicare. It provides protection if you pay high drug costs or have unexpected prescription drug bills. It doesn't cover all costs. You have to pay part of the cost of prescription drugs. Most people also have to pay an additional monthly cost.

Private companies provide Medicare prescription drug coverage. You choose the drug plan you like best. Whether or not you should sign up depends on how good your current coverage is. You need to sign up as soon as you are eligible for Medicare. Otherwise, there may be additional charges.

Medicare drug coverage helps pay for prescription drugs you need. It's optional and offered to everyone with Medicare. Even if you don’t take prescription drugs now, consider getting Medicare drug coverage. If you decide not to get it when you’re first eligible, and you don’t have other creditable prescription drug coverage (like drug coverage from an employer or union) or get Extra Help, you’ll likely pay a late enrollment penalty if you join a plan later. Generally, you’ll pay this penalty for as long as you have Medicare drug coverage. To get Medicare drug coverage, you must join a Medicare-approved plan that offers drug coverage. Each plan can vary in cost and specific drugs covered. 

There are 2 ways to get Medicare drug coverage:

1. Medicare drug plans. These plans add drug coverage to Original Medicare, some Medicare Cost Plans, some Private Fee‑for‑Service plans, and Medical Savings Account plans. You must have Medicare Part A (Hospital Insurance) and/or Medicare Part B (Medical Insurance) to join a separate Medicare drug plan.

2. Medicare Advantage Plan (Part C) or other Medicare Health Plan with drug coverage. You get all of your Part A, Part B, and drug coverage, through these plans. Remember, you must have Part A and Part B to join a Medicare Advantage Plan, and not all of these plans offer drug coverage.

To join a Medicare drug plan, Medicare Advantage Plan, or other Medicare health plan with drug coverage, you must be a United States citizen or lawfully present in the United States.

Visit Medicare.gov/plan-compare to get specific Medicare drug plan and Medicare Advantage Plan costs, and call the plans you’re interested in to get more details. For help comparing plan costs, contact your State Health Insurance Assistance Program (SHIP).

How to join a drug plan

Once you choose a Medicare drug plan, here's how to get prescription drug coverage:

• Enroll on the Medicare Plan Finder or on the plan's website.
• Complete a paper enrollment form.
• Call the plan.
• Call us at 1-800-MEDICARE (1-800-633-4227). TTY: 1-877-486-2048.

When you join a Medicare drug plan, you'll give your Medicare Number and the date your Part A and/or Part B coverage started. This information is on your Medicare card.

Consider all your drug coverage choices

Before you make a decision, learn how prescription drug coverage works with your other drug coverage. For example, you may have drug coverage from an employer or union, TRICARE, the Department of Veterans Affairs (VA), the Indian Health Service, or a Medicare Supplement Insurance (Medigap) policy. Compare your current coverage to Medicare drug coverage. The drug coverage you already have may change because of Medicare drug coverage, so consider all your coverage options.

If you have (or are eligible for) other types of drug coverage, read all the materials you get from your insurer or plan provider. Talk to your benefits administrator, insurer, or plan provider before you make any changes to your current coverage.

Joining a Medicare drug plan may affect your Medicare Advantage Plan  

If you join a Medicare Advantage Plan, you’ll usually get drug coverage through that plan. In certain types of plans that can’t offer drug coverage (like Medical Savings Account plans) or choose not to offer drug coverage (like certain Private Fee-for-Service plans), you can join a separate Medicare drug plan. If you’re in a Health Maintenance Organization, HMO Point-of-Service plan, or Preferred Provider Organization, and you join a separate drug plan, you’ll be disenrolled from your Medicare Advantage Plan and returned to Original Medicare.

You can only join a separate Medicare drug plan without losing your current health coverage when you’re in a:

• Private Fee-for-Service Plan
• Medical Savings Account Plan
• Cost Plan
• Certain employer-sponsored Medicare health plans

Talk to your current plan if you have questions about what will happen to your current health coverage.

All plans must cover a wide range of prescription drugs that people with Medicare take, including most drugs in certain protected classes,” like drugs to treat cancer or HIV/AIDS. A plan’s list of covered drugs is called a “formulary,” and each plan has its own formulary. Medicare drug coverage typically places drugs into different levels, called “tiers,” on their formularies. Drugs in each tier have a different cost. For example, a drug in a lower tier will generally cost you less than a drug in a higher tier.

List of covered prescription drugs (formulary)

Most Medicare drug plans (Medicare drug plans and Medicare Advantage Plans with prescription drug coverage) have their own list of what drugs are covered, called a formulary. Plans include both brand-name prescription drugs and generic drug coverage. The formulary includes at least 2 drugs in the most commonly prescribed categories and classes. This helps make sure that people with different medical conditions can get the prescription drugs they need. All Medicare drug plans generally must cover at least 2 drugs per drug category, but plans can choose which drugs covered by Part D they will offer.

The formulary might not include your specific drug. However, in most cases, a similar drug should be available. If you or your prescriber (your doctor or other health care provider who’s legally allowed to write prescriptions) believes none of the drugs on your plan’s formulary will work for your condition, you can ask for an exception .

A Medicare drug plan can make some changes to its drug list during the year if it follows guidelines set by Medicare. Your plan may change its drug list during the year because drug therapies change, new drugs are released, or new medical information becomes available.

Plans offering Medicare drug coverage under Part D may immediately remove drugs from their formularies after the Food and Drug Administration (FDA) considers them unsafe or if their manufacturer removes them from the market. Plans meeting certain requirements also can immediately remove brand name drugs from their formularies and replace them with new generic drugs, or they can change the cost or coverage rules for brand name drugs when adding new generic drugs. If you’re currently taking any of these drugs, you’ll get information about the specific changes made afterwards.

For other changes involving a drug you’re currently taking that will affect you during the year, your plan must do one of these:

• Give you written notice at least 30 days before the date the change becomes effective.
• At the time you request a refill, provide written notice of the change and at least a month’s supply under the same plan rules as before the change.

You may need to change the drug you use or pay more for it. You can also ask for an exception. Generally, using drugs on your plan’s formulary will save you money. If you use a drug that isn’t on your plan’s drug list, you’ll have to pay full price instead of a copayment or coinsurance, unless you qualify for a formulary exception. All Medicare drug plans have negotiated to get lower prices for the drugs on their drug lists, so using those drugs will generally save you money. Also, using generic drugs instead of brand-name drugs may save you money.

Generic drugs

The Food and Drug Administration (FDA) says generic drugs are copies of brand-name drugs and are the same as those brand-name drugs in:

• dosage form
• safety
• strength
• route of administration
• quality
• performance characteristics
• intended use

Generic drugs use the same active ingredients as brand-name prescription drugs. Generic drug makers must prove to the FDA that their product works the same way as the brand-name prescription drug. In some cases, there may not be a generic drug the same as the brand-name drug you take, but there may be another generic drug that will work as well for you. Talk to your doctor or other prescriber about your generic drug coverage.

Tiers

To lower costs, many plans offering prescription drug coverage place drugs into different “tiers" on their formularies. Each plan can divide its tiers in different ways. Each tier costs a different amount. Generally, a drug in a lower tier will cost you less than a drug in a higher tier.

Here's an example of a Medicare drug plan's tiers (your plan’s tiers may be different):

• Tier 1—lowest copayment : most generic prescription drugs
• Tier 2—medium copayment: preferred, brand-name prescription drugs
• Tier 3—higher copayment: non-preferred, brand-name prescription drugs
• Specialty tier—highest copayment: very high cost prescription drugs

In some cases, if your drug is in a higher tier and your prescriber (your doctor or other health care provider who’s legally allowed to write prescriptions) thinks you need that drug instead of a similar drug in a lower tier, you or your prescriber can ask your plan for an exceptionto get a lower coinsurance or copayment for the drug in the higher tier. Plans can change their formularies at any time. Your plan may notify you of any formulary changes that affect drugs you’re taking.

Medicare drug coverage includes drugs, like buprenorphine, to treat opioid use disorders. It also covers drugs, like methadone, when prescribed for pain. However, Medicare Part A covers methadone when used to treat an opioid use disorder as a hospital inpatient, and Part B now covers methadone when you get it through an opioid treatment program. Contact the plan for its current formulary, or visit the plan’s website. 

NEW INSULIN BENEFIT! The cost of a one-month supply of each Part D-covered insulin is capped at $35 and you don't have to pay a deductible. If you get a 60- or 90-day supply of insulin, your costs can’t be more than $35 for each month’s supply of each covered insulin.

Employer or union coverage

This is health coverage from your, your spouse’s, or other family member’s current or former employer or union. If you have drug coverage based on your current or previous employment, your employer or union will notify you each year to let you know if your drug coverage is creditable. Keep the information you get. Call your benefits administrator for more information before making any changes to your coverage.

COBRA

There may be reasons why you should take Medicare drug coverage instead of, or in addition to, COBRA. If you take COBRA and it includes creditable prescription drug coverage, you'll have a special enrollment period to join a Medicare drug plan without a penalty when COBRA ends.

Talk with your State Health Insurance Assistance Program (SHIP) to see if COBRA is a good choice for you. If you have questions about Medicare and COBRA, call the Benefits Coordination & Recovery Center at 1-855-798-2627 (TTY: 1-855-797-2627).

Medicare Supplement Insurance (Medigap) policy with prescription drug coverage

It may be to your advantage to join a Medicare drug plan because most Medigap drug coverage isn't creditable. You may pay more if you join a drug plan later.

Medigap policies can no longer be sold with prescription drug coverage, but if you have drug coverage under a current Medigap policy, you can keep it. If you join a Medicare drug plan, your Medigap insurance company must remove the prescription drug coverage under your Medigap policy and adjust your premiums. Call your Medigap insurance company for more information.

Medicaid

Your drug costs are covered by Medicare. You'll need to join a Medicare drug plan for Medicare to pay for your drugs.

In most cases, you'll pay a small amount for your covered drugs. If you have full coverage from Medicaid and live in a nursing home, you pay nothing for covered prescription drugs.

If you have full coverage from Medicaid and live in an assisted living or adult living facility, or a residential home, you'll pay a small copayment for each drug.

If you don't join a drug plan, Medicare will enroll you in one to make sure you don't miss a day of coverage. If you decide you want another plan, you can switch to another plan at any time.

Supplemental Security Income Benefits

If you get benefits or help from your state Medicaid program paying your Medicare premiums, you need to join a Medicare drug plan for Medicare to cover your drugs. You automatically qualify for 

Extra Help with your prescription drug costs. If you don't join a plan, Medicare will enroll you in one to make sure you don't miss a day of coverage.

State Pharmaceutical Assistance Program

Each state decides how its State Pharmaceutical Assistance Program (SPAP) works with Medicare prescription drug coverage. Some states give extra coverage when you join a Medicare drug plan. Some states have a separate state program that helps with prescriptions. Contact your SPAP to get more information.

Long-term care facility

Long-term care pharmacies contract with Medicare drug plans to provide drug coverage to their residents. If you're entering, living in, or leaving a nursing home, you'll have the opportunity to choose or switch your Medicare drug plan. This allows you to choose a plan that contracts with your nursing home's pharmacy.

HUD housing assistance

If you get housing assistance from the Department of Housing and Urban Development (HUD), you may want to join a Medicare drug plan.

If you qualify for Extra Help, you won't lose your housing assistance. However, your housing assistance may be reduced as your prescription drug spending decreases. The value of the Extra Help paying your drug costs will make up for any decrease in your housing assistance.

Food stamps

If you get food stamps, you may want to join a Medicare drug plan. If you qualify for Extra Help, your food stamp benefits may decline, but that decline will be offset by Extra Help.

If you're near the food stamps eligibility cutoff, you may lose your minimum food stamp benefits because you’ll be paying less for your prescription drugs. The value of the Extra Help paying your drug costs will make up for any decrease in food stamp benefits.

Health Insurance Marketplace

A service that helps people shop for and enroll in affordable health insurance. The federal government operates the Marketplace, available at HealthCare.gov, for most states. Some states run their own Marketplaces.

The Health Insurance Marketplace (also known as the “Marketplace” or “exchange”) provides health plan shopping and enrollment services through websites, call centers, and in-person help.

The types of insurance listed below are all considered creditable prescription drug coverage. If you have one of these types of insurance, in most cases, it will be to your advantage to keep your current coverage. 

Federal Employee Health Benefits (FEHB) Program

This is health coverage for current and retired federal employees and covered family members. These plans include creditable prescription drug coverage, so you don’t need to get Medicare drug coverage. However, if you decide to get Medicare drug coverage, you can keep your FEHB plan, and in most cases, Medicare will pay first. For more information, visit opm.gov/healthcare-insurance/healthcare, or call the Office of Personnel Management at 1‑888‑767‑6738. Visit opm.gov/retirement-services/benefits-officers-center/agency-benefits-officers for a list of Benefits Officers. You can also call your plan if you have questions.

Veterans' Benefits

This is health coverage for veterans and people who have served in the U.S. military. You may be able to get drug coverage through the U.S. Department of Veterans Affairs (VA) program. You may join a Medicare drug plan, but if you do, you can’t use both types of coverage for the same drug at the same time. For more information, contact the VA.

TRICARE (military health benefits)

This is a health care program for active‑duty service members, military retirees, and their families. Most people with TRICARE who are entitled to Part A must also have Part B to keep their TRICARE drug benefits. If you have TRICARE, you don’t need to join a Medicare drug plan. However, if you do, your Medicare drug plan pays first, and TRICARE pays second.

If you join a Medicare Advantage Plan with drug coverage, your Medicare Advantage Plan and TRICARE may coordinate their benefits if your Medicare Advantage Plan network pharmacy is also a TRICARE network pharmacy. Otherwise, you can file your own claim to get paid back for your out-of-pocket costs. For more information, visit tricare.mil, or call the contact the TRICARE Pharmacy Program at 1-877-363-1303. TTY users can call 1‑877‑540‑6261. 

Civilian Health and Medical Program of the Department of Veterans Affairs (CHAMPVA)

This is a comprehensive health care program in which the Department of Veterans Affairs shares the cost of covered health care services and supplies with eligible beneficiaries. You may join a Medicare drug plan, but if you do, you won’t be able to use the Meds by Mail program which can give your maintenance drugs to you at no charge (no premiums, deductibles, and copayments). For more information, visit va.gov/communitycare/programs/dependents/champva/ or call CHAMPVA at 800-733-8387.

Indian Health Services

The IHS is the primary health care provider to the American Indian/Alaska Native Medicare population. The Indian health care system, consisting of tribal, urban, and federally operated IHS health programs, delivers several clinical and preventive health services through a network of hospitals, clinics, and other entities. Many Indian health facilities participate in the Medicare drug program. If you get prescription drugs through an Indian health facility, you’ll continue to get them at no cost to you, and your coverage won’t be interrupted. Joining a Medicare drug plan or Medicare Advantage Plan with drug coverage may help your Indian health facility because the plan pays the Indian health facility for the cost of your prescription drugs.

Talk to your local Indian health benefits coordinator who can help you choose a plan that meets your needs and tell you how Medicare works with the Indian health care system.

You may find it necessary to get help paying for prescriptions even after enrolling in Medicare Drug Coverage (Part D). For example, you may reach the annual spending limit and enter what is called the coverage gap. Here are 5 tips to consider if you think you might need to get help with the costs of prescription drug coverage.

1. Consider switching to generics or other lower-cost drugs.

There may be generic or less-expensive brand-name drugs that would work just as well as the ones you're taking now. Talk to your doctor to find out if these are an option for you. You might also be able to lower prescription costs by using mail-order pharmacies.

2. Choose a Medicare drug plan that offers additional coverage during the gap.

There are plans that offer additional coverage during the Medicare drug coverage gap, like for generic drugs. However, plans with additional gap coverage to help pay for prescriptions may charge a higher monthly premium.

Check with the drug plan first to see if your drugs would be covered during the gap. Find health & drug plans.

3. Pharmaceutical Assistance Programs. 

Some pharmaceutical companies offer programs to help pay for medications for people enrolled in Medicare drug coverage (Part D). Find out whether there’s a Pharmaceutical Assistance Program that can lower prescription costs for the drugs you take.

4. State Pharmaceutical Assistance Programs.

Many states and the U.S. Virgin Islands offer help paying for prescriptions, drug plan premiums and/or other drug costs. Find out if your state has a State Pharmaceutical Assistance Program.

5. Apply for Extra Help.

Medicare and Social Security have a program called Extra Help—a way for people with limited income and resources to get help with prescription costs. If you qualify for Extra Help, you could pay no more than:

• $4.15 for each generic covered drug in 2023
• $10.35 for each brand-name covered drug in 2023