Which of the following best describes "coinsurance"?

Coinsurance is best described as a cost-sharing model where both the insurer and the insured pay a percentage of the costs of covered healthcare services. This arrangement typically kicks in after the insured has met their deductible, meaning that once the deductible is paid, the remaining costs are split between the insurance company and the policyholder according to a predetermined percentage. For instance, in a common terms structure, if the coinsurance is set at 80/20, the insurer would cover 80% of the costs after the deductible is met, with the insured being responsible for the remaining 20%. This structure encourages policyholders to utilize services judiciously, as they remain financially responsible for a portion of their healthcare costs, promoting cost-awareness and responsible use of medical resources.