The National Association of Independent Schools (NAIS) is a U.S.-based membership organization for private, nonprofit, K-12 schools. Founded in 1963, NAIS represents independent schools and associations in the United States, including day, boarding, and day/boarding schools; elementary and secondary schools; boys', girls', and coeducational schools. NAIS has affiliate members internationally as well. NAIS's mission is to be the national voice of independent schools and the center for collective action on their behalf.