This longitudinal study examined (a) the second-grade reading outcomes of 368 children who participated in either experimental or school-designed supplemental intervention in kindergarten, and (b) the influence and interactions of learner variables and type of intervention on reading achievement. Descriptive findings indicated that percentages of students identified as at risk or not at risk were statistically comparable between interventions. Entry-level letter identification scores predicted performance on all second-grade reading outcomes for students in both interventions. The influence of entry-level sound matching, receptive vocabulary knowledge, English language learner status and reading outcomes was moderated by type of intervention. Performance on a curriculum-embedded measure administered 8 weeks into intervention reliably predicted second grade reading performance.