United States (US) immigration policies have increasingly focused on national security resulting in universities experiencing declines in international student applications, constraints on international scholar employment, and complications facilitating international research collaborations. The COVID-19 pandemic brought additional travel restrictions, embassy closures, and health and safety concerns that exacerbated these challenges. Science mobility is critical for science education, training, competitiveness, and innovation. Using a representative sample of US and foreign-born scientists in three STEM fields, we explore how recent visa and immigration policies have shaped research collaborations, work with students and postdoctoral scholars, and intentions to leave. We use descriptive statistics, analysis of variance, and logistic regression and find academic scientists report disruptions from visa and immigration policies; negative impacts of immigration policies on US higher education; negative effects on recruitment and retention of international trainees; and increased intentions to leave the US driven by negative perceptions of immigration policy.