Medicare can be pretty complex, and you’ll likely find terms you’ll need to familiarize yourself with regarding your coverage. Coinsurance (or cost-sharing) is one of the many terms you’ll see when dealing with your coverage. Below we’ll discuss how Medicare defines coinsurance and how it works.

How Medicare Coinsurance Works

Much like other popular insurance terms and expenses, you’ll find that coinsurance is something you’ll pay with nearly every part of Medicare, although you can expect those costs to vary. Let’s find out how coinsurance works and how much you can expect to pay in coinsurance amounts, depending on your coverage.

Medicare Part A Coinsurance

Medicare Part A coverage is part of your Original Medicare coverage. Part A helps cover any inpatient care you need, whether an inpatient hospital stay, hospice, or nursing facility. Part A doesn’t have coinsurance for your first 60 days as an inpatient. Once admitted for 60 days, coinsurance or copays will begin.

Hospitalisations revolve around benefit periods. So, the day you are admitted into the hospital, your benefit period begins. You’ll find below the copayment amounts that you can expect to pay during benefit periods:

  • $0 coinsurance for days 1-60.
  • [GCBB#part-a-inpatient-coinsurance-days-61-90] copayment each day for days 61-90.
  • [GCBB#part-a-inpatient-coinsurance-days-91-120] for every lifetime reserve day of days 91 and more.
  • $0 for the first 20 days in a skilled nursing facility (SNF), and then [GCBB#part-a-snf-copay-days-21-100] for days 21-100. Once you exceed 100 days, you’ll be responsible for all remaining costs.

You must cover the remaining healthcare costs once you use your lifetime reserve days. In addition to Medicare-defined coinsurance costs, you’ll also need to pay your deductibles and applicable premiums.

Medicare Part B Coinsurance

Medicare Part B helps cover your outpatient medical care. This outpatient care includes doctors’ appointments, medical equipment, and more. You’ll pay a Medicare-defined coinsurance of 20% of the Medicare-approved costs.

Before your coinsurance kicks in, you must cover your $240 deductible first. In addition to your coinsurance and deductible costs, you’ll also be responsible for paying a monthly premium.

Your Part B premium cost will depend on your annual income. Most people have a monthly premium of $174.70, but that cost may dramatically rise if you have a much higher income.

Preventative Services That Don’t Have Coinsurance Under Medicare Part B

Preventive services are a variety of covered services you’ll receive through Medicare at no cost. Preventive services typically won’t have Medicare coinsurance amounts for you to pay, as long as your doctor accepts the Medicare assignment. Some of the most popular preventative services are:

How Medicare Advantage Coinsurance Works

Medicare Advantage policies (also known as Medicare Part C) work as a replacement for Original Medicare. But instead of going directly through Medicare, you’re purchasing your policy through a private insurance company that contracts with Medicare, so you can still have Part A and B health coverage.

In addition to Medicare Part A and B coverage, Medicare Advantage plans generally cover drug, dental, and vision coverage in some cases.

Your coinsurance and other payment amounts will vary when you have Medicare Advantage coverage. Costs can range depending on how in-depth your plan coverage is and which insurance company you choose.

A lot of Medicare Advantage policies will charge copayments rather than coinsurance. Premiums and deductibles will also vary depending on your type of Part C coverage.

How Medicare Supplement Coinsurance Works

With costs like coinsurance, copays, annual deductibles, and premiums, many people decide to buy a Medicare Supplement policy. These policies can help dramatically reduce all of your out-of-pocket costs. Currently, 10 Medigap policies are available to purchase, and each one varies in price and coverage.

Every Supplement plan covers your Part A coinsurance completely. Most Medigap plans fully cover your Part B coinsurance, while some only cover Part B coinsurance at 50% and 75%.

Medigap plans K and L will cover 100% of your coinsurance costs once you meet your Part B deductible and out-of-pocket annual limit costs.

How Medicare Part D Coinsurance Works

Part D is your prescription drug coverage. Since Part A only covers inpatient care and Part B covers outpatient care, many people are left without drug coverage unless they buy Part D coverage.

Your coinsurance expense will vary depending on your chosen plan and the various drug costs. Different prescription drug plans cover different medications (such as brand-name drugs) at various prices.


It’s common to have many questions when learning about Medicare and all the costs you must cover. Here are some of the most common questions among Medicare beneficiaries.

How is Medicare coinsurance calculated?

You can calculate your coinsurance costs by following these steps:

  • First, convert your percentage amount. You’ll do this by moving the decimal to the left by two spaces.
  • Next, multiply the above decimal amount by your insurance-approved amount for the health care service you received.
  • Your coinsurance amount (decimal figure) X the total cost = Your coinsurance amount
  • Your coinsurance amount is based on your network’s approved amount.

Let’s take a look at an example:

Molly’s insurance plan has a 20% coinsurance to fill her new prescription. The network’s approved amount owed for this medication is $120. 0.20 X $120.00 = $24.00 So, Molly will owe a coinsurance amount of $24.00 for her new prescription.

Do Medicare patients have coinsurance?

Medicare patients will have coinsurance costs depending on their coverage level and healthcare services.

What is the coinsurance for Original Medicare?

You won’t have to pay coinsurance with Part A for your first 60 days as an inpatient in a hospital and the first 20 days if staying in a skilled nursing facility. Once you exceed 60 days in a hospital, your coinsurance is [GCBB#part-a-inpatient-coinsurance-days-61-90].

Once you exceed 91 days as an inpatient, your coinsurance is [GCBB#part-a-inpatient-coinsurance-days-91-120]. For Part B, you’ll need first to meet your deductible. Then, your coinsurance will be 20% of the Medicare-approved cost.

How is coinsurance defined?

Coinsurance is an amount you, the Medicare beneficiary, must pay for health services with your Medicare plan.

What does coinsurance mean in Medicare Part D?

Coinsurance is the amount determined by your Part D insurance company of the amount you’ll pay. Your coinsurance costs will vary depending on your Part D plan and coverage.

What is the difference between a premium and a coinsurance?

You’ll pay an insurance premium for your plan, usually monthly. You must continue paying this premium to keep your health policy active. Coinsurance is a percentage of your bill you’ll spend with your insurance carrier.

What is the difference between coinsurance and copays?

Coinsurance refers to the percentage of medical bills you’ll be responsible for after meeting your deductible. You pay in conjunction with your insurance plan. Copays are set dollar amounts you’ll be responsible for when receiving medical care, like a doctor’s visit. You’ll likely have different copay amounts for specialist visits, urgent care visits, etc.

How to Get Help Paying for Medicare Coinsurance

The Medicare program is a great comprehensive form of health insurance. But you’ll still pay a fair share of Medicare costs even with being as extensive as it is. Between Medicare-defined coinsurance, deductibles, copays, and premiums, you’ll likely open your wallet more than a few times throughout the year to pay for your health plan.

When you purchase a Medicare Supplement plan, you also choose to save money! Supplemental coverage can help you save BIG and will help cover your coinsurance costs. Call us today to find out more, or fill out our online quote form. Let our team of agents do the homework and get you the most comprehensive plan at the best rate!

Written By:
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Lindsay Malzone, Lindsay Malzone is the Medicare editor for She's been contributing to many well-known publications since 2017. Her passion is educating Medicare beneficiaries on all their supplemental Medicare options so they can make an informed decision on their healthcare coverage.
Reviewed By:
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Rodolfo Marrero, Rodolfo Marrero is one of the co-founders at He has been helping consumers find the right coverage since the site was founded in 2013. Rodolfo is a licensed insurance agent that works hand-in-hand with the team to ensure the accuracy of the content.