"Don't Ask, Don't Tell" was repealed four years ago. This Tuesday, Defense Secretary Ashton Carter extended the full range of discrimination protections to gays and lesbians. It's been a long time coming. But some 15,000 transgender troops are not included, often despite years of distinguished service — including combat. Many are recognized for who they are by their comrades and their commanders, but officially they are not "fit to serve." We hear about a historic moment—and who's being left behind.