The Library District is supported by a secondary property tax rate of $0.097 per $100 assessed valuation. Each year, the Library District receives State Grants-in-Aid funds for $23,000. This amount is distributed equally among the member libraries and used for library-related expenses and projects. The Pinal County Library District administers support services to twelve affiliate libraries and operates one facility (San Tan Valley). Three libraries are located in unincorporated communities (Arizona City, Oracle, and San Manuel) and are staffed by volunteers. The remaining nine (excluding San Tan Valley) are municipal libraries with paid staff (Apache Junction, Casa Grande, Coolidge, Eloy, Florence, Kearny, Mammoth, Maricopa, and Superior). These twelve libraries are affiliates, not branches. The relationship is established through Intergovernmental Agreements with the county library district, which sets out the terms of cooperation.