Police say the small projectile hit the nine-year-old boy in the lower chest and is now lodged near his liver.
The boy was shot Saturday night while playing in his backyard.
He says he heard a loud bang and then ran inside to tell his parents, who took him to a hospital where he was treated for non life-threatening injuries.
Doctors decided not to remove the projectile because the operation would have been too intrusive.
Police say based on the size of the entry wound they believe he was hit by a pellet or BB from an air gun.