A copayment, or copay, is a cappe contribution defined in the policy and paid by an insured person each time a medical service is accessed. It must be paid before any policy benefit is payable by an insurance company. Copayments do not usually contribute towards any policy out-of-pocket maximums. Insurance companies use copayments to share health care costs to prevent moral hazard. Though the copay is often only a small portion of the actual cost of the medical service, it is thought to prevent people from seeking medical care that may not be necessary (eg: an infection by the common cold), which can result in substantial savings for insurance companies. The underlying philosophy is that with no copay, the perception is that medical care is "free" and then is used more often.