The objective of this investigation was to examine how instructional practices in 107 first- and second-grade classrooms in 17 high poverty schools moderate the impact on literacy outcomes of literacy-related skills students bring to the classroom. Ratings of teaching effectiveness and time allocation to literacy activities were obtained. Twenty time allocation variables were reduced into seven patterns of literacy activities that were examined as predictors of reading and spelling outcomes. Students' initial reading ability and interactions of teaching effectiveness ratings by time allocation components predicted reading and spelling outcomes. Discussion centers on immutable versus flexible views of reading development and analytic approaches to examining instructional practices.