From the plain language summary: "Research shows that external implementation support (EIS) can help successfully implement and scale up interventions. However, less is known about the experience of those receiving EIS, which may provide clues about the range of effectiveness reported from EIS studies. This report examines information from participants across 13 regions in North Carolina and South Carolina and their EIS support team about the feasibility of engaging in the support relationship. Ratings across several measures suggest that EIS is experienced favorably and is feasible for participants across different contexts. Further research into the feasibility and usability of other support models would help refine the field and illuminate insights to accelerate successful and sustainable implementation."