How to Calculate Coinsurance
- 1). Read your insurance policy and note the deductible and coinsurance rate for a particular expense.
- 2). Subtract the deductible amount from the cost of the expense covered by the plan.
- 3). Multiply the result from step 2 by your coinsurance percentage. The result is the amount you will pay in coinsurance. For instance, if you get $5,000 worth of dental work done, you have a $1,000 deductible and your coinsurance rate is 10 percent, the amount you pay in coinsurance would be: (5000-1000)*(0.10) = $400.
- 4). Add the result from step 3 to your deductible. This is the total amount of you will have to pay toward the expense. In the example from step 3, the total cost would be $1,400.