Political and societal pressures are influencing kindergarten teachers and their classroom practices on a national level. Teachers' receptivity to reforms depends to a large degree on their buy-in to the change effort. Drawing on analyses of interviews with kindergarten teachers across school and districts, this study examined teacher buy-in to an increased academic focus in kindergarten and in turn the factors that influence buy-in. Research Findings: Analyses revealed that kindergarten teachers in the same schools and districts had qualitatively different responses to the increased academic focus in kindergarten. Teachers' professional identity, sense of control, and interactions with school leaders emerged as factors influencing teacher buy-in. Practice or Policy: The role of teacher buy-in as a crucial component in times of change is discussed. Specifically, situating reforms in the context of implementation science and teacher well-being is discussed.