The present application is directed to an expandable intervertebral device. One context in which the device may be used is a corpectomy procedure to replace one or more vertebral members. The device is adjustable between a first orientation with a first overall height, and a second orientation with a second overall height. The device generally includes an inner member, an outer member, and a gear. Rotation of the gear causes relative movement between the inner and outer members to move between the first and second orientations and adjust the overall height.