This study compared the effects of Tier 2 reading interventions that operated in response-to-intervention contexts. Kindergarten children (N = 90) who were identified as at risk for reading difficulties were stratified by school and randomly assigned to receive (a) Early Reading Intervention (ERI; Pearson/Scott Foresman, 2004) modified in response to student performance or (b) their schools' typical supplemental reading intervention (regrouping and curriculum pacing adjustments). In both conditions, intervention was provided 30 minutes per day in small groups for approximately 100 sessions. Results indicated no statistically significant group differences on any outcome measures. Between-group effect sizes revealed substantively important differences (Valentine & Cooper, 2003) favoring the ERI responsive condition on multiple measures with effect sizes ranging from 0.35 to 0.59. Overall, findings indicated that the majority of students in both Tier 2 intervention conditions performed above the 30th percentile on posttest measures of word reading measures. (Contains 1 figure and 5 tables.)