Given the proliferation of college promise programs and the increasing popularity of last-dollar designs, we explore changes to states' financial aid resource environments following the adoption of two of the largest and longest-operating state programs: Tennessee Promise and Oregon Promise. We leverage descriptive tools and a causal-inference difference-in-differences design to document how the overall level of financial aid per student changed following adoption, as well as how the composition of an "average" aid award changed. We show there were significant increases in total grant aid per student and that these increases were driven almost exclusively by higher state investments. In tandem with this increased reliance on state aid, however, we also detect substitution effects away from institutional grants. Our findings not only expand the growing body of evidence on promise programs and financial aid generally but also have important implications for policy. If promise programs fundamentally alter states' overall aid environments, including by changing the level of aid available per student and by increasing reliance on a specific (and potentially precarious) source of aid, these changes not only have implications for the fiscal sustainability of programs themselves but also for ultimate student outcomes. [This is the online first version of an article published in "The Journal of Higher Education."]