The invention is a subtalar implant able to expand after implantation. The subtalar implant has two or more expansion segments or wings. In all forms, the expansion wings are hinged on the distal portion of the subtalar implant which causes only the proximal portion of the wing to expand relative to the midplane of the implant. The expansion wings and the entire subtalar implant are threaded to prevent the implant from backing out of the sinus tarsi once implanted. In one form, the subtalar implant includes an integral expansion screw that, when rotated, expands the expansion wings. In another form, the subtalar implant includes a separate expansion screw that, when rotated, expands the expansion wings. The integral and the separate expansion screw includes a socket that accepts a like driver tool for rotating the expansion screw and expanding the expansion wings.