There are many misunderstandings about Medicare coverage, especially prescription drug coverage. The four parts (A, B, C, and D) cover different healthcare services, from hospital stays and doctor visits to prescription drugs and other benefits.

Medicare parts B and D both offer prescription drug coverage under different federally set guidelines. While Medicare Part B only covers select types of medications under specific conditions, Medicare Part D offers broader drug coverage.

Both require you to pay premiums based on your income and there are copays, deductibles, and other out-of-pocket costs. We’ll look at the specific differences in prescription coverage between parts B and D.

Medicare Part B coverage includes many outpatient health and medical services, such as:

There are out-of-pocket costs you will pay for Part B including premiums, deductibles, and coinsurance. The rates change from year to year, and your out-of-pocket costs also depend on your earned income.

The average monthly premium for Part B in 2022 is $170.10, and the annual deductible is $233.

In addition, you must pay 20 percent coinsurance for certain services after meeting your deductible. This includes doctor’s fees and medications.

Medigap supplementary plans can help with coinsurance and other out-of-pocket costs.

Medicare Part B covers some prescription drugs depending on if you meet specific criteria. Most medications covered by Part B are administered by a health professional.

Some examples of medications Part B covers include:

Medications account for a large part of costs for beneficiaries. Almost $1 for every $5 spent on Medicare services is for medications.

A few medications are responsible for a large majority of money spent on Medicare Part B drug costs. Part B covers some very expensive medications, such as:

Medicare Part D covers most of the outpatient medications that you would get from your local pharmacy, mail-order pharmacy, or another pharmacy provider.

Depending on the plan, Part D covers medications not covered by parts A or B. Plans are offered by private insurance companies and there are many choices based on where you live.

Enrollment happens between October 15 and December 7 every year during open enrollment. You’re not automatically enrolled, and there’s a late enrollment penalty if you don’t have some type of drug coverage.

Medicare requires all plans to cover at least two medications from the most prescribed therapeutic classes.

Part D does not cover:

Part D plans must cover medications from these six classes:

Individual plan costs vary depending on:

  • where you live
  • your income
  • coverage you want
  • what you want to pay out of pocket

Medicare Part D is an important benefit to help pay for prescription drug costs. Medicare pays a large part of drug costs but you still have to pay some portion. Since the cost of medications has steadily increased over the years, having Part D coverage can save you significantly on your medications.

Also, even though Part D is voluntary, if you don’t have some drug coverage, there’s a penalty that will be added to your premium forever. So, it’s beneficial to select a part D plan when you’re eligible, even if you currently don’t take any medications.

Finding a Medicare prescription drug plan

  • Visit the Medicare website or call 800-633-4227.
  • Find a navigator to help with your questions.
  • Talk to a state navigator about local plans.

There are several options when it comes to choosing Medicare Part B and Part D plans for prescription drug coverage.

They offer different prescription coverage, and it’s usually not an either/or choice. You may need both plans to save the most on your prescription drug costs depending on your healthcare needs.

When choosing a plan, consider the following:

  • what medications are covered
  • if your doctor and pharmacy are on the plan
  • the out-of-pocket costs
  • the plan rating (5-star plans are more expensive)
  • if you need injections at the doctor’s office
  • each plan’s limits for medication coverage
  • if you need supplemental insurance
  • the other costs that don’t count toward your out-of-pocket costs

The table below summarizes how parts B and D compare:

Part BPart D
Coverageflu, pneumococcal, hepatitis B vaccines; insulin used in pumps, oral cancer, ESRD, transplant drugs; professionally administered injections and infusionscommercially available vaccines not covered by Part B, insulin not given by pump, most oral medications, infusions or injections not covered by Part B
Eligibilityage 65 or older, qualifying disability, or diagnosis of ESRD or ALSthose enrolled in Part A and/or Part B
Costs in 2022$170.10 monthly premium for most people, $233 annual deductible, 20% coinsurance on covered services and itemspremium and copayment/ coinsurance costs depend on your plan

  • Medicare parts B and D cover prescription medications in different ways based on meeting eligibility criteria. Most people have both plans to help pay for medications depending on their overall health.
  • Part B covers only select medications, while Part D covers many medications you get from your local pharmacy or other pharmacy providers.
  • There are many plans and eligibility rules based on your income, what you want to pay out of pocket, and what type of coverage you want.
  • For those who need it, Medicare can also help with premiums and out-of-pocket costs through the Extra Help program.

Medicare plan options and costs are subject to change each year.