What is meant by "co-insurance" in health insurance?

Co-insurance refers to the arrangement in health insurance where the insured is responsible for paying a certain percentage of medical costs after they have met their deductible. This means that once the individual has paid their deductible amount, which is out-of-pocket costs they must cover before the insurance kicks in, they share the subsequent costs of healthcare services with the insurance company.

For example, if a health insurance policy has a co-insurance rate of 20%, after the deductible is met, the insured would pay 20% of each medical bill while the insurance would cover the remaining 80%. This type of cost-sharing is designed to promote responsible use of healthcare services, as individuals will have some financial stake in the cost of their treatment.

The other options describe different concepts related to health insurance but do not capture the essence of co-insurance. Full payment by the insurer does not involve any shared expense; the out-of-pocket maximum relates to the cap on total expenses one would pay; and the provider network is about the selection of healthcare providers rather than the financial arrangement between insurer and insured.