Rural Spectrum Accessibility Act of 2015

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 serving certain rural areas. Defines "small carrier" 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. Provides carriers receiving such licenses and participating in the program with a three-year extension of licenses granted under this Act.