Considering the importance of a diverse science, technology, engineering, and math (STEM) research workforce for our country's future, it is troubling that many underrepresented racial minority (URM) students start graduate STEM programs, but do not finish. However, some institutional contexts better position students for degree completion than others. The purpose of this study was to uncover the academic and social experiences, power dynamics, and programmatic/institutional structures URM students face within their graduate STEM programs that hinder or support degree progression. Using a critical socialization framework applied in a cross-comparative qualitative study, I focused on how issues of race, ethnicity, and underrepresentation within the educational contexts shape students' experiences. Data was collected from focus group interviews involving 53 URM graduate students pursuing STEM disciplines across three institution types - a Predominately White Institution, a Hispanic-Serving Institution, and a Historically Black University. Results demonstrate that when students' relationships with faculty advisors were characterized by benign neglect, students felt lost, wasted time and energy making avoidable mistakes, had less positive views of their experiences, and had more difficulty progressing through classes or research, which could cause them to delay time to degree completion or to leave with a master's degree. Conversely, faculty empowered students when they helped them navigate difficult processes/milestones with regular check-ins, but also allowed students room to make decisions and solve problems independently. Further, faculty set the tone for the overall interactional culture and helping behavior in the classroom and lab contexts; where faculty modeled collaboration and concern for students, peers were likely to do the same. International peers sometimes excluded domestic students both socially and academically, which had a negative affect on intergroup dynamics and limited the opportunities for learning among URM students. Interestingly, students describe peer dynamics that occasionally suggest racial undertones in interactions; however, many students were unaware of implications on their training experiences or were simply uncomfortable naming racism. Prevailing racial stereotypes even impacted students trained in welcoming and culturally respectful programs. The study expands studies on URM graduate students, socialization theory, and formal and informal structures in programs that can assure success in graduate school.