A provision of health insurance or third-party payment that requires the individual who is covered to pay part of the cost of medical care received.

Cost-sharing may be in the form of
- a deductible: a fixed amount paid by the insured person before any insurance benefit occurs
- a copayment: a fixed amount paid by both parties
- a co-insurance: a payment set in proportion to the cost of a service

World Health Organization. European Observatory on Health Systems and Policies. Glossary. 2009.