His last speaking role was in Season 2 episode "Chickenpox". Since then he faded to an occasional background character and never appeared within the McCormick household. He is still within the McCormick household due to him been seen in the "The List" while the family were eating dinner and at that moment Kenny got shot, and in "Sexual Healing" where he can be seen sitting at the living room and at Kenny's funeral.
Kevin has a plaster on his forehead. He first appeared with his family in the episode "Starvin' Marvin", but actually, he is one of the characters whose first appearance is being argued. A retarded-sick boy who resembles Kevin was seen in special bus for disabled kids.
Episodes in which he appeared