Food handler's permits are issued by county health departments, and prices are determined at a state level. For example, in Oregon a first time food handler's permit costs $10, while a replacement permit is only $5.
Any establishment serving or preparing food for public consumption is required to have at least one certified individual on site at any time that food is being prepared. Owners and managers of food service businesses typically maintain their certifications so that regular employees do not need to. However, hourly employees working without a permit should still be able to demonstrate a functional understanding of food safety.