A model of developmentally appropriate practice in helping teachers grow is described. The model derives from a consideration of the psychological processes by which adults learn, and our desire to teach adults by the same methods we hope they will use in teaching children. The model includes a sequence of six kinds of interactions that the teacher trainer engages in with the teacher, from building trust to eliciting self-exploration. The concrete actions we take to create these kinds of interactions are described. This model of professional development was applied by a statewide project to increase the quality of child care in 150 classrooms serving primarily children from low-income families. Initial evaluations suggest it is working as hoped.