The shooting occurred about 2:45 a.m. Monday on Richardson County Road 717 near U.S. Highway 75, about 10 miles south of Auburn.
Richardson County Sheriff Randy Houser says the deputy had noticed a stopped car, so he approached to offer help to the people inside. Houser says several shots were fired from inside the vehicle, which then sped away.
The deputy gave a chase but soon stopped when he noticed that one of his arms had been hit by a bullet.
The officer is being treated in Lincoln. His name hasn’t been released.
No arrests have been reported.