The purpose of the Teacher Follow-up Survey is to provide information about teacher mobility and attrition. It is a one-year follow-up of a sample of 8,400 teachers who were originally selected for the Teacher questionnaire of the Schools and Staffing Survey (SASS). The study asked three questions: (1) Who is most likely to leave; (2) why do they move or leave; and (3) where are they likely to go? Data in this report link responses from the 2000?01 school year to characteristics of those same teachers who participated in SASS during the 1999?2000 school year. Within this report, there are some data that are drawn directly from the 1999?2000 SASS. Results reveal that teachers with less than 10 years of expereince, techers under the age of 30, and teachers from private schools were more likely to leave than others in the sample. Among the reasons that public school teachers gave for moving to a new school were an opportunity for a better teaching assignment, dissatisfaction with support from administrators, and dissatisfaction with workplace conditions. Teachers who left tended to go from private to public schools, and private school teachers were more likely to move to occupations outside of education rather than were public school teachers. Appended are: (1) Standard Error Tables; (2) Technical Notes; and (3) Description of Variables. (Contains 14 tables.)