research and education and to strengthen economic competitiveness through training the next generation of science research leaders. IRES focuses on the development of a world-class U.S. STEM workforce through international research experiences for cohorts of U.S. students. Student participants supported by IRES funds must be citizens, nationals, or permanent residents of the United States. Students do not apply directly to NSF to participate in IRES activities. Students apply to NSF-funded investigators who receive IRES awards. To identify appropriate IRES projects, students should consult the directory of active IRES awards. All PIs, co-PIs and Senior Personnel on IRES proposals must be from U.S. based organizations. Personnel from international partners should be listed as "non-NSF funded collaborators." Guidance on information to provide for "non-NSF funded collaborators" is found in Section V.A. IRES projects engage a group of undergraduate and/or graduate students in active high-quality collaborative research, in principle at an international site with mentorship from international researchers. IRES projects must be organized around a coherent overarching intellectual theme that may involve a single discipline or multiple disciplines funded by NSF. For all IRES proposals, PIs are strongly encouraged to outline a variety of virtual, hybrid or other alternative approaches to strengthen and maintain international collaboration in addition to travel. It is expected that these approaches will extend collaboration beyond the actual international trip and strengthen IRES proposals overall.