If children do not learn how to read in the first few years of primary school, they will struggle to complete the cycle and are at greater risk of dropping out. It is therefore crucial to identify and test interventions that have the potential of making a large impact, can be implemented quickly, and are affordable to be taken to scale by the Kenyan government. This is the goal of the PRIMR Initiative--to test various options for improving learning outcomes and instruction in Kenyan schools, using a randomized controlled design. The design is essential to this contribution, as many pilot programs in the sector do not test the impacts of quality-improvement methods at a medium scale and with enough rigor to identify a causal impact. In this paper, the authors focus on early-grade literacy outcomes--reading fluency and comprehension--after one year of implementation for pupils in grades 1 and 2. Study findings indicated that the first year of PRIMR had a positive impact on the three outcomes of interest--oral reading fluency, the percentage of pupils who read at the MOE's benchmark, and reading comprehension--although not on all combinations of language, grade, and school type. Also, the meaningful first-year impacts of PRIMR on student achievement have implications for teacher professional development in Kenya. One table and one figure are appended.