The Advancing Informal STEM Learning (AISL) Program is committed to funding research and practice, with continued focus on investigating a range of informal STEM learning (ISL) experiences and environments that make lifelong learning a reality. This Program seeks proposals that center equity and belonging, and further the well-being of individuals and communities who have historically been and continue to be excluded, underserved, or underrepresented, due to gender, race, ethnicity, sexual orientation, disability status, neurodiversity, geographic location, and economic status, among others, as well as their intersections. The current solicitation encourages proposals from institutions and organizations that serve public audiences, and specifically focus on public engagement with and understanding of STEM, including community STEM; public participation in scientific research (PPSR); science communication; intergenerational STEM engagement; and STEM media. Projects funded by AISL should contribute to research and practice that further illuminates informal STEM learnings role in equity and belonging in STEM; personal and educational success in STEM; advancing public engagement in scientific discovery; fostering interest in STEM careers; creating and enhancing the theoretical and empirical foundations for effective informal STEM learning; improving community vibrancy; and/or enhancing science communication and the publics engagement in and understanding of STEM and STEM processes. The AISL Program funds five types of projects: (1) Synthesis; (2) Conference; (3) Partnership Development and Planning; (4) Integrating Research and Practice; and (5) Research in Support of Wide-reaching Public Engagement with STEM. NOTE: Activities primarily focused on formal educational systems or outcomes are outside the scope of work supported by this program. AISL does not fund formal elementary, middle, or high school, or undergraduate or graduate education, whether in-person or online. Similarly, AISL does not fund formal workforce training (e.g., professional certifications and degree-earning programs) that is not aimed directly at informal STEM learning professionals.