The present study evaluated the effectiveness of a non-randomized summer reading program offered by a school district meeting or exceeding all National Summer Learning Project recommendations. The district had 10 years of experience delivering the program to Grades 1-5 students with or at risk of reading disabilities. Voluntary participation had been declining in the three years prior to the pandemic and declined further during the pandemic. In 2021, 144 eligible students attended at least half the summer program and 1113 students were eligible but did not participate. All students were pre- and post-tested with a measure of overall reading ability. After propensity score weighting, the data from each grade were analyzed using multilevel models. Results revealed no statistically significant differences between the treatment and control groups, nor did special education and free or reduced-price lunch status significantly moderate outcomes. Implications for future summer reading programs are discussed.