James Holmes, a 19-year veteran of the Hillside force, had pleaded guilty in June to aggravated assault in connection with the August 2009 incident at his Toms River home.
The shooting occurred after the teen and his mother had a heated argument. She called Toms River police and Holmes, who arrived before officers got to the home.
Holmes became involved in the dispute and eventually fired a round from his .40-caliber service weapon into the teen's leg. The boy has since recovered from his wound.
The 49-year-old Holmes, who was sentenced Friday, remains suspended without pay from his police post.