Background: The Iranian health system is based on social health insurance, which is responsible for providing access to basic health care. In addition to basic treatment insurance, complementary health insurance (CHI) offers introductory packages that include surplus services. We recently observed an increase in Iran's health insurance loss coefficient, from 16.5% to 90.4% in 2017.Aim: To determine the willingness to pay (WTP) for (CHI).Methods: We attempted to determine the WTP for CHI in this study to understand better the potential market and the factors that influence CHI demand. The study surveyed 1023 households in the Kerman Province. A questionnaire developed by the researcher was used in this study, based on the principles of contingent valuation and the bidding game method principles. In each scenario, the factors affecting people's WTP, the demand function, and the effective factors on demand were determined using linear multivariate regression using the ordinary least squares method.