Underprepared students at community colleges are often assigned to a sequence of developmental education (DE) courses that can substantially delay, or even halt, their progress to degree completion. In 2014, Florida took a drastic step forward when it implemented a comprehensive DE reform. Our findings show large, positive base effects of the reform for all students as well as heterogeneous effects by high school academic preparation. More specifically, students in the two lowest tracks of high school academic preparation--students for whom much of the reform was explicitly designed--experienced greater gains than did students in the upper two tracks. However, students in the upper tracks also experienced gains and students in the lowest track experienced the greatest gains of all. These findings suggest that when statewide DE reform was implemented in Florida, all students benefited, with the least prepared students experiencing the greatest gains.