An expandable intervertebral implant for insertion between vertebrae of a human spine is described. The expandable intervertebral implant includes an upper body that engages a first vertebra of the human spine, a lower body that engages a second vertebra of the human spine, an insert, and a spacer. The insert may be positioned between an inferior surface of the upper body and a superior surface of the lower body. The insert may be engaged to increase a separation distance between the lower body and the upper body. A spacer may be inserted between the upper body and the lower body to maintain the increased separation distance between the upper body and the lower body after expansion of the intervertebral implant in the human spine.