In Chile, Mexico, Turkey and the United States (until 2014), health insurance coverage is voluntary at least for a part of the population. In Chile, employees in the formal sector must enrol in a health insurance plan and pay 7% of their monthly income or pension for coverage. They can choose to enrol with the public insurance fund, called Fonasa, which covers around 76% of the population or with one of the thirteen private health insurance funds (Isapres). Seven private funds are competing in an open market, while others are associated with public enterprises and their employees.