The Principal Follow-Up Survey, 2016–17 (PFS 16/17) is a data collection that is part of the National Teacher and Principal Survey program; program data are available since 2017 at https://nces.ed.gov/pubsearch/licenses.asp. PFS 16/17 (https://nces.ed.gov/surveys/ntps/overview.asp?OverviewType=6) is a longitudinal follow-up to the National Teacher and Principal Survey, 2015–16 (NTPS 2015–16) data collection. PFS 16/17 determined mobility patterns of principals in the base (NTPS 2015–16) school year. The PFS 16/17 sample includes all schools whose principals completed questionnaires in NTPS 2015–16. Schools and principals were mailed the PFS questionnaire. Nonrespondents were followed-up via telephone. Key statistics produced from PFS 16/17 include the number of principals that still worked as a principal in the same school in the following school year, how many moved to become a principal in another school, how many left the principalship altogether, and from those who left the principalship, what percentage retired or sought work in another occupational field.