The type of insurance in which the insured pays a percentage of the claim. co-payment co-insurance deductible premium

## Step 1
The problem is asking us to identify the type of insurance where the insured pays a percentage of the claim. The options provided are co-payment, co-insurance, deductible, and premium.

## Step 2
Let's define each term:
- Co-payment: This is a fixed amount that the insured pays for a specific service, regardless of the total cost of the service.
- Co-insurance: This is a type of insurance where the insured pays a percentage of the claim. This percentage is usually between 20% and 80%.
- Deductible: This is the amount that the insured must pay out-of-pocket before the insurance company begins to pay.
- Premium: This is the amount that the insured pays to the insurance company, usually on a monthly basis, to keep the insurance policy.

## Step 3
Based on the definitions, the term that best fits the description given in the problem is co-insurance.