The Percentage You Pay After Your Deductible
After you meet your deductible, you might expect your insurance to cover everything. Instead, most plans split the remaining cost between you and your insurer using a percentage-based system. If you have ever wondered what is co insurance, it is this cost-sharing arrangement that determines how much of each medical bill you are responsible for after your deductible has been satisfied.
What is co insurance in practical terms? It is typically expressed as a ratio, such as 80/20. The insurer pays 80 percent and you pay 20 percent of covered services until you reach your out-of-pocket maximum. According to Healthcare.gov, coinsurance is one of the primary ways health insurance plans share costs with members.
Understanding how coinsurance works helps you predict your medical expenses and choose the right plan. Let’s break it down with real numbers and real scenarios.
How Coinsurance Works Step by Step
Coinsurance kicks in after you have paid your deductible for the year. Before that point, you typically pay the full allowed amount for covered services. Once the deductible is met, you and your insurer begin splitting costs according to your coinsurance rate.
Here is an example. You have a plan with a $2,000 deductible and 20 percent coinsurance. You need a procedure that costs $10,000. Assuming you have not met any of your deductible yet, you pay the first $2,000. The remaining $8,000 is subject to coinsurance. You pay 20 percent of $8,000, which is $1,600, and your insurer pays the other $6,400. Your total bill is $3,600.
This cost-sharing continues for every covered service until your total out-of-pocket spending for the year reaches your plan’s maximum. After that, the insurer covers 100 percent.
Common Coinsurance Ratios and What They Mean
Health plans use different coinsurance splits depending on the plan tier. Understanding these ratios helps you compare options during open enrollment.
An 80/20 plan is one of the most common arrangements. The insurer pays 80 percent and you pay 20 percent. A 70/30 plan shifts more cost to you, while a 90/10 plan reduces your share. Bronze plans on the ACA Marketplace typically have higher coinsurance rates, such as 40 percent, while Gold and Platinum plans offer lower rates around 20 percent or less.
The trade-off is straightforward. Plans with lower coinsurance rates usually have higher monthly premiums. Plans with higher coinsurance rates come with lower premiums but expose you to greater costs when you actually use medical services. The Kaiser Family Foundation reports that the average coinsurance rate for in-network specialist visits in employer plans was around 19 percent in recent surveys.
Coinsurance vs. Copay
These two terms describe different types of cost-sharing, and they work differently at the point of care. A copay is a fixed dollar amount you pay for a specific service, such as $30 for a doctor visit or $15 for a generic prescription. Coinsurance is a percentage of the total allowed cost.
With a $40 copay, you know exactly what you will owe before you walk into the office. With 20 percent coinsurance, your cost depends on the total bill. A specialist visit billed at $300 with 20 percent coinsurance costs you $60. The same visit with a $40 copay costs you $40 regardless of the billed amount.
Many plans use both. You might pay copays for routine office visits and prescriptions while paying coinsurance for hospitalizations, surgeries, and other major services. For a deeper comparison, see our guide on copay vs coinsurance.
How Coinsurance Applies to Different Services
Your coinsurance rate can vary depending on the type of service and whether you stay in-network.
In-Network vs. Out-of-Network
Most plans have different coinsurance rates for in-network and out-of-network providers. You might pay 20 percent coinsurance in-network but 40 percent out-of-network. Beyond the higher percentage, out-of-network providers can also charge more than the plan’s allowed amount, leaving you responsible for the difference through balance billing.
Hospital and Surgical Services
Inpatient hospital stays and surgeries are where coinsurance has the biggest financial impact. A $50,000 surgery at 20 percent coinsurance means $10,000 out of your pocket, though your out-of-pocket maximum limits the total. This is why understanding your maximum alongside your coinsurance rate is so important.
Prescription Drugs
Some plans apply coinsurance rather than flat copays to prescription drugs, particularly specialty medications. A biologic drug costing $5,000 per month at 30 percent coinsurance would cost you $1,500 per fill. Many plans cap specialty drug costs or offer assistance programs to offset these expenses.
Coinsurance and Your Out-of-Pocket Maximum
Coinsurance payments count toward your annual out-of-pocket maximum. Once your deductible payments, copays, and coinsurance payments add up to that limit, your plan pays 100 percent of covered services for the rest of the year.
Using the earlier example with a $2,000 deductible, 20 percent coinsurance, and a $7,000 out-of-pocket maximum: after paying the $2,000 deductible, you have $5,000 remaining before hitting your cap. At 20 percent coinsurance, you would need $25,000 worth of additional covered services before your coinsurance payments alone reach that remaining $5,000. After that, full coverage kicks in.
How to Minimize Your Coinsurance Costs
Several strategies can help you reduce the amount you pay through coinsurance.
Stay in-network. The difference between in-network and out-of-network coinsurance can double or triple your share. Always verify that your provider, facility, and any specialists involved in your care are in-network before receiving services.
Use a health savings account or flexible spending account to pay coinsurance with pre-tax dollars. This effectively gives you a discount equal to your marginal tax rate. If you are in the 22 percent tax bracket, paying coinsurance from an HSA saves you 22 cents on every dollar.
Compare plans during open enrollment with your expected medical usage in mind. If you anticipate high medical costs, a plan with lower coinsurance and a higher premium may save you money overall. Run the numbers using your anticipated procedures and prescriptions.
Frequently Asked Questions
Do I pay coinsurance before or after my deductible?
After. Coinsurance applies only to covered services once you have met your annual deductible. Before the deductible is met, you pay the full allowed amount for most services. Some plans cover certain services with a copay before the deductible, but coinsurance for the bulk of medical care begins after the deductible threshold.
Does coinsurance apply to preventive care?
Under the ACA, most preventive services are covered at 100 percent with no cost-sharing, meaning no coinsurance, copay, or deductible applies. This includes annual wellness exams, recommended vaccinations, and specific screenings. Once a visit shifts from preventive to diagnostic, coinsurance may apply.
Can my coinsurance rate change during the year?
Your coinsurance rate is fixed for the plan year. It cannot change until your plan renews, typically on January 1 for calendar-year plans. However, if you switch plans mid-year through a qualifying life event, the new plan’s coinsurance rate applies going forward.
Is 20 percent coinsurance good?
A 20 percent coinsurance rate is among the most common and generally considered favorable for the consumer. It means your insurer covers 80 percent of costs after your deductible. Lower coinsurance rates like 10 percent are better but usually come with higher premiums. Higher rates like 30 or 40 percent reduce premiums but increase your risk for large bills.
Making Coinsurance Work in Your Favor
Coinsurance is one of those insurance terms that seems abstract until you face a significant medical bill. Knowing your coinsurance rate, understanding when it applies, and pairing it with a clear picture of your deductible and out-of-pocket maximum gives you the tools to plan and budget for healthcare costs. Compare plans based on total potential costs rather than premiums alone, and always confirm network status before receiving care. For a comprehensive look at how all of these costs interact, visit our healthcare costs guide.