A middle expanded, removable disk implant for stabilizing adjacent vertebrae. The implant is detachably mounted to an applicator for insertion into the anatomical region between two adjacent vertebrae from which a portion of the intervertebral disk has been removed, and once inserted, is positioned by anterior-posterior movement in the disk space to the position in which both the expanded, larger diameter middle portion and the smaller diameter end portions of the implant engage the bodies of the adjacent vertebrae. Also provided is a method of lumbar intervertebral disk stabilization using a stabilizer comprised of implant and applicator.