What Is Coinsurance?
Published on June 25, 2025
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Coinsurance is the percentage of a medical bill that you’re responsible for after you’ve met your deductible.
Think of it as an agreement with your insurance company to share costs: You each pay a portion of the bill, which adds up to 100 percent.
How Does Coinsurance Work?
If you have health insurance and you’ve reached your deductible, you may have to pay coinsurance. Typically, your provider will send you a bill detailing what you owe after they’ve worked out the costs with your insurance company. The amount you pay is usually a fixed ratio, so you’ll be responsible for the same percentage of a charge each time.
Many insurance companies offer an 80/20 coinsurance plan. This means the insurance company pays 80 percent of the bill, while you pay the remaining 20 percent. But some plans will set your responsibility at other amounts, such as 10 percent, 30 percent, or even 40 percent.
Some insurance plans don’t provide any coinsurance. In this case, you may be responsible for the entire bill, or your insurance company might pick up the whole tab.
How Do I Calculate My Coinsurance Cost?
Your coinsurance amount will depend on your health plan. If you have an 80/20 coinsurance split with your insurance company, a $100 doctor’s bill will look like this:
- You’ll pay $20 (20 percent).
- Your insurance company will pay $80 (80 percent).
Remember, you always have to hit your deductible before coinsurance kicks in.
What’s the Difference Between Coinsurance and Copay?
Coinsurance is not the same as a copay, which is a payment you make for a specific health service. While both coinsurance and copays are out-of-pocket costs, there are some key differences between the two.
Coinsurance
Copay
A percentage you pay of medical costs (example: 20 percent of a bill)
A flat fee you pay for medical care, such as office visits or prescription medications (example $20 per doctor’s visit)
Kicks in after you meet your deductible
Usually doesn’t count toward your deductible*
Is billed by your provider after you receive the service and your insurance approves the charges
Is due at the time of service
Counts toward your out-of-pocket maximum
Counts toward your out-of-pocket maximum
What’s the Difference Between Coinsurance and a Deductible?
A deductible is the amount you have to pay before your insurance company starts its coverage. Once you reach that amount, your coinsurance kicks in, and you start sharing the bill with your insurance company.
For example, if you have a $2,000 deductible, you will be required to pay all of that first. Then, your insurance will split the rest of the costs with you according to your coinsurance rate.
Certain preventive services, like screenings and checkups, may be paid by your insurance company without requiring you to meet your deductible first.
How Does Coinsurance Differ for In-Network vs. Out-of-Network?
Your coinsurance rates may be higher if you go to a doctor or hospital that your insurance doesn’t work with. In fact, your insurance may not cover any out-of-network care. That leaves you with the entire bill to pay. It’s important to understand your specific policy and what it covers for in-network and out-of-network care.
Is There a Maximum Out-of-Pocket for Coinsurance?
Coinsurance payments go toward your out-of-pocket maximum. Once you hit your maximum for the year, you won’t have to pay coinsurance any longer. Your insurance will cover 100 percent of your costs for the rest of the year.
The Takeaway
- Coinsurance is the percentage of medical costs you pay after you reach your deductible.
- Most health insurance companies offer an 80/20 split, which means they will cover 80 percent of the bill, while you will pay for 20 percent.
- Coinsurance payments go toward your out-of-pocket maximum. When you reach this amount, your insurance will cover all costs for you.
Resources We Trust
- Healthcare.gov: In-Network Coinsurance
- Healthinsurance.org: What Is Coinsurance?
- Kaiser Permanente: Glossary of Eligibility and Benefits Terms
- Texas Department of Insurance: Do You Know the Difference Between a Copay and Coinsurance?
- U.S. Department of Health and Human Services: What Are the Medicare Premiums and Coinsurance Rates?
EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
- In-Network Coinsurance. Healthcare.gov.
- Do You Know the Difference Between a Copay and Coinsurance? Texas Department of Insurance. April 17, 2025.
- What Is Coinsurance? Healthinsurance.org.
- What Is Coinsurance: Definition & How It Works. MetLife. March 19, 2025.
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Sarah Goodell, MA
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Sarah Goodell is a health policy consultant with over 25 years of experience. She is currently working as an independent consultant focusing on the Affordable Care Act, Medicare, h...
Julie Lynn Marks
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Julie Marks is a freelance writer with more than 20 years of experience covering health, lifestyle, and science topics. In addition to writing for Everyday Health, her work has bee...