Staff Sgt. Robert Hudson was also given a bad-conduct discharge despite his appeal at a hearing last week that he be allowed to remain in the service so he could provide for his family.
"He cared only about himself when it was his duty to care about them," prosecutor Capt. Drew Cutler told the court at Joint Base San Antonio-Lackland in Texas.
Hudson was the 18th Lackland instructor to be prosecuted in the recruit-abuse scandal. Seventeen of the defendants have been convicted.
Hudson pleaded guilty to six charges in exchange for dismissal of an assault charge, the San Antonio (Texas) Express-News said.