Rural Spectrum Accessibility Act of 2017 This bill directs the Federal Communications Commission to establish a program under which a wireless carrier receiving a license under specified provisions of the Communications Act of 1934 may partition or disaggregate the license in order to make unused spectrum available to small carriers or carriers to serve certain rural areas. A "small carrier" is defined as a carrier with not more than 1,500 employees as calculated under regulatory standards used by the Small Business Administration to determine the number of individuals employed by a business concern on a full-time, part-time, or other basis. A three-year license extension is provided to any carrier that receives such a license and participates in the program.