Many prior studies have examined whether there are average differences in levels of teaching effectiveness among graduates from different teacher preparation programs (TPPs); other studies have investigated which features of preparation predict graduates' average levels of teaching effectiveness. This is the first study to examine whether there are average differences between TPPs in terms of graduates' average growth, rather than levels, in teaching effectiveness, and to consider which features predict this growth. Examining all graduates from Tennessee TPPs from 2010 to 2018, we find meaningful differences between TPPs in terms of both levels and growth in teaching effectiveness. We also find that different TPP features, including areas of endorsement, program type, clinical placement type and length, program size, and faculty composition explain part of these differences. Yet, the features that predict initial teaching effectiveness are not the same features that predict growth.