The goal of this report is to provide administrators, school psychologists, counselors, special educators, and reading specialists with a summary and analysis of the evidence that supports the use of reading interventions in grades 1–3. The review was limited to studies of Tier 2 interventions, those designed to provide preventive services to students at risk for reading difficulties. The initial literature search identified 1,813 articles and reports. After screening them for relevance and conducting a detailed What Works Clearinghouse (WWC) analysis of the rigor of the study designs, the review team determined that only 23 effectiveness studies met WWC evidence standards (Version 3.0). Of those, 22 resulted in either significant, positive, or potentially positive impacts in at least one area of reading. None produced negative outcomes. Twelve of the 13 grade 1 interventions and all seven interventions for grades 2 and 3 produced positive or potentially positive effects. Effects were strongest and most consistent in the area of word and pseudoword reading. Several also produced effects in reading comprehension and passage reading fluency. Reading vocabulary was rarely assessed. Both individually administered and small-group interventions resulted in positive or potentially positive outcomes, although especially in grade 1, more of the interventions were one-on-one. In all cases, the interventionist received some training prior to implementing the intervention. However, these studies differed from common school practice in that implementation was carefully monitored in virtually all instances and coaching or feedback was provided. It is unclear how generalizable these findings are when the typical amount of ongoing support for interventionists is far more limited in practice.