The STEM Early College Expansion Project is an effort to integrate STEM strategies with the early college model and implement this in comprehensive high schools. This report summarizes findings from two separate quasi-experimental impact studies of the model in Michigan and Connecticut. Results from Michigan showed statistically significant impacts on enrollment in college-level courses and on attainment of college credits. Treatment schools in Michigan also had descriptively lower dropout rates. The Connecticut impact study had challenges with the study design that resulted in an inability to make clear causal claims about the impact.