An expandable interbody device used as a prosthesis during spinal surgery. The expandable interbody device is configured to be inserted into the space between spinal disks to provide stability. The expandable interbody device includes a drive block, a linkage block, a drive screw, a first endplate, a second endplate, and at least two linkages. Rotation of the drive screw causes movement of the linkage block relative to the drive block and/or movement of the first endplate relative to the second endplate.