The goals of the Accelerating Research through International Network-to-Network Collaborations (AccelNet) program are to accelerate the process of scientific discovery and prepare the next generation of U.S. researchers for multiteam international collaborations. The AccelNet program supports strategic linkages among U.S. research networks and complementary networks abroad that will leverage research and educational resources to tackle grand research challenges that require significant coordinated international efforts. The program seeks to foster high-impact science and engineering by providing opportunities to cooperatively identify and coordinate efforts to address knowledge gaps and research needs. This solicitation invites proposals for the creation of international networks of networks in research areas aligned with a grand challenge identified as a priority by the research community or NSF, such as the NSF Big Ideas or in an activeprogram solicitation. AccelNet awards support the connections among research networks, rather than supporting fundamental research as the primary activity. Each network of networks is expected to engage in innovative collaborative activities that promote synergy of efforts across networks and provide professional development for U.S. students, postdoctoral scholars, and early-career researchers. Two proposal categories covered by this solicitation include:Design and Implementation. It is strongly recommended that prospective PIs contact the AccelNet Program Officer(s) to ascertain that the focus and budget of their proposed activities are appropriate for this solicitation.