This study examines the impact of "Promise" programs on postsecondary institutions' decision-making. Promise programs have garnered widespread attention in the U.S., especially after the announcement of the Kalamazoo Promise, but relatively little scholarly research. Promise programs provide grant aid to all students from a particular geographic location and make an early financial aid commitment. Using a 2000-2014 panel dataset, this paper employs a quasi-experimental difference-in-difference methodological design to consider the impact of Promise programs on postsecondary institutional behavior. The authors find that Promise programs influence behavior related to tuition and fee setting, and grant aid awards. They also uncover a notable finding that two- and four-year institutions do not react to Promise programs in the same manner. [This paper was presented in 2016 at the Association for Education Finance and Policy, the American Educational Research Association, the Midwest Political Science Association, and the 2015 Illinois Education Research Council.]