A coordinated response by a trained multidisciplinary team (MDT) can help support child sex trafficking (CST) victims, but little is known about factors that influence the development and sustainability of MDTs in this work. An online survey was conducted with 171 professionals who attended a Multidisciplinary Team Child Sex Trafficking (MDT-CST) training to identify factors related to team growth. Increased MDT success was related to: (1) the presence of a CST-specific advocacy organization in the community; (2) other community agencies active in supporting CST victims (e.g., SANE nurses, faith-based organizations, and runaway shelters); (3) a greater breadth of professional representation on the MDT; and (4) agency leadership support for the CST action plan. Most of the MDTs sustained and increased their coordination with other community agencies over time, but the study identified that growth is improved when administrators support team efforts and there are resources and supports for CST victims elsewhere in the community.