Recent advances concerning emerging/beginning reading skills, positive behavioral support (PBS), and three-tiered schoolwide prevention models combined with federal mandates (i.e., IDEA and No Child Left Behind) have stimulated interest in providing early and intensive instructional intervention services to children at risk for reading and behavior problems. New measures for identifying students as early as kindergarten who are not acquiring early basic literacy skills make this possible. However, questions regarding exactly how to formulate, deliver, sustain, and manage secondary-level interventions remain to be addressed. This paper describes first-year, first-grade findings for students participating in secondary-level interventions (i.e., small-group reading instruction) in a randomized trial of the efficacy of secondary and tertiary reading and behavior interventions under way at the Center for Early Intervention in Reading and Behavior, University of Kansas. The formulation of the experimental secondary-level intervention was guided by evidence supporting the efficacy of (a) small groups of 3 to 6 participating students and low student-teacher ratio combined with (b) explicit, phonics-based instruction. Selected curricula were Reading Mastery, Proactive Reading, Programmed Reading, and Read Well, use of which varied by choice across experimental-group schools. PBS was an additional intervention context in experimental schools. Comparison schools and first-grade teachers did not employ the three-tiered model, early screening, or PBS; most students were taught using conventional whole-group instruction, little or no individualization, and curricula with weak scientific evidence. Initial results indicate significantly larger growth for experimental secondary-level at-risk students than for comparisons. Experimental-group first graders not showing growth were those identified with disabilities or behavioral risks and English language learners. Implications are discussed.