Career Substitute - The career substitute teacher does the job as a career. They do it because they like students. This type of substitute is generally cool and friendly and has lots of experience with kids. They like to stay in the same school district or at the same school and fill in as needed. The determining factor for the Career Sub is that, as a student, you see them frequently, for several years, in the same school or district. Career subs like to substitute teach and plan on doing it some more. The Retired Teacher and Retired Veteran classes mentioned by Zarkon often fall under this one.