Background
Learning to read is foundational to student success in early elementary school, however many students are not proficient readers by third grade. A large body of research suggests high-impact tutoring is the most effective intervention to help struggling readers, however it can be hard to implement and scale. 

Aims 
This study presents results from a randomized controlled trial of an early elementary reading tutoring program designed to be feasible at scale. 

Sample 
Participants were 818 kindergarten students in a large southeastern district in the US who were classified as emergent readers on the district's screening tool. 

Methods 
Within kindergarten classrooms, eligible students were randomly assigned to receive supplementary early literacy tutoring during the 2021-22 school year. The program embeds part-time tutors into the classroom to provide short bursts of instruction to individual students over the course of the school year. With the support of technology, tutors deliver a sequenced curriculum to students. At the end of the school year, students completed program and district literacy assessments. 

Results 
Students assigned to the program were over two times more likely to reach the program's target reading level by the end of kindergarten (70% vs. 32%) and scored 0.23-standard deviations higher on an oral reading fluency test than the control group. The results were largely homogenous across student populations and extended to district-administered assessments. 

Conclusions 
The results at the end of the first year of implementation provide promising evidence of an affordable and sustainable approach for delivering one-on-one personalized reading tutoring at scale.