According to AG Opinion AGO 2005 No. 5, “Existing statutory law prohibits public libraries from charging fees for traditional library services, such as borrowing books or reviewing materials at the library. Libraries may charge fees for services which are beyond the traditional purposes of a library and are provided as a convenience for the public.”
This Opinion reaffirms AGO 1992 No. 31, which notes that the library can charge a fee to nonresidents.