The United States Agency for International Development (USAID) is inviting concept papers for the Implementation Science for Strengthening Family Health (IS4FH) initiative, aimed at enhancing access to voluntary family planning and improving the timing and spacing of births. This opportunity seeks to fund one or multiple awards through a Cooperative Agreement, with a total funding ceiling of $35 million for core and field activities, emphasizing the importance of evidence generation and utilization in family health interventions. Eligible applicants include U.S. and non-U.S. organizations, institutions of higher education, and NGOs, with a focus on collaborative partnerships and capacity building. Interested parties must submit their concept papers by May 30, 2029, and can reach out to Marcus M Moon at mmoon@usaid.gov for further inquiries.