The Less Commonly Taught and Indigenous Languages Partnership, funded by the Andrew W. Mellon Foundation, was housed in the Center for Language Teaching Advancement (CeLTA) at Michigan State University from 2016-2025. This cross-university initiative utilized the established and widely recognized strengths within the Big Ten Academic Alliance to collaboratively develop models of less commonly taught language (LCTL) instruction reflecting best practices in proficiency-oriented instruction. The project included research in LCTL proficiency assessment, goal setting, curricular and technological innovations, as well as teacher education and professional development.