Almost 30 states in the U.S. have authorized their community colleges to confer baccalaureate degrees without a partnership with a traditional four-year institution. The intention of four-year degree programs at select community colleges is to increase four-year degree production in areas with high labor market demand but a low supply of qualified workers. High-demand areas include science, technology, engineering, and mathematics (STEM) fields such as nursing, computer technology, and science education. Previous studies show that direct and indirect costs associated with completing the four-year STEM degree at traditional four-year institutions serve as barriers to program completion and impact historically underserved students disproportionately. Community colleges in the U.S. reduce impediments to earning a bachelor's degree in STEM by offering a more affordable and accessible route. Community colleges also serve a diverse population of students, potentially affecting the number of minority and marginalized students pursuing and completing the four-year STEM degree. This study sought to determine the impact of community college baccalaureate (CCB) degree programs on three main post-CCB implementation effects: state-level differences in the overall number of four-year STEM degrees awarded, the number of STEM degrees awarded to women, Black, and Hispanic students, and state-level changes in the proportion of women, Black, and Hispanic students earning STEM baccalaureate degrees. I used a difference-in-differences (DiD) research design and extracted degree completion data from the Integrated Postsecondary Education System (IPEDS) for all degree-granting U.S. public and private two-year and four-year institutions to compose a national dataset. The dataset spanned years 1990 to 2019, with treatment occurring in multiple years across states. The treatment group for this study comprised states with an active CCB policy, CCB STEM program, and CCB STEM graduates. The control group encompassed states lacking these characteristics. I found mixed results for the overall number of four-year STEM degrees produced at the state level and no statistically significant effects elsewhere. Therefore, I conclude that CCB-implementation has had minimal impact on four-year STEM degree attainment in the short term. The results of this study inform policymakers of the effectiveness of CCB programs and their ability to increase four-year STEM degrees, especially for historically underserved students. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]