Large-scale initiatives to expand evidence-based practices are often poorly implemented and rarely endure. The purpose of this study was to identify the perceived barriers and facilitators to sustainment of an evidence-based supported employment program, Individual Placement and Support (IPS). Within a 2-year prospective study of sustainment among 129 IPS programs in 13 states participating in a national learning community, we interviewed IPS team leaders and coded their responses to semi-structured interviews using a conceptual framework adapted from another large-scale implementation study. Leaders in 122 agencies (95%) that sustained their IPS programs identified funding, prioritization, and workforce characteristics as both key facilitators and barriers. Additional key factors were lack of local community supports as a barrier and leadership and structured workflow as facilitators. Within the IPS learning community, team leaders attributed the sustainment of their program to funding, prioritization, workforce, agency leadership, and structured workflow. The actions of the learning community's leadership, state governments, and local programs together may have contributed to the high sustainment rate.