The national academy of sciences was formed under a charter passed as an ACT of incorporation by the united states congress and signed into law on march 3, 1863. NAS operates as a private membership organization of distinguished scholars engaged in scientific, engineering, or medical research. NAS is dedicated to the furtherance of science for the general welfare. NAS provides advice and other services to the u.s. Government and other private sponsors. NAS is exempt from federal income taxes under section 501(c)(3) of the internal revenue code, except for unrelated business income.