The ulnar collateral ligament (UCL) is at risk of injury in overhead throwing athletes, including Major League Baseball (MLB) position players. This injury sometimes necessitates elbow UCL reconstruction, known as Tommy John surgery. Our research looked at return-to-sport (RTS) for MLB position players, postoperative career length, pre- and postoperative performance, and position changes after reconstruction. It shows a RTS rate for MLB position players after Tommy John surgery is similar to that of pitchers. Catchers had a significantly shorter career length than that of matched controls. Outfielders performed worse postoperatively versus preoperatively. There is a high rate of position change post reconstruction for infielders and outfielders.