In order to meet the growing needs of a diverse range of information users and constituents, the delivery of timely and effective climate services frequently requires collaboration across geopolitical boundaries. This session will explore the opportunities, obstacles, and evolving solutions associated with transboundary climate services, drawing upon concrete experiences within the North American Climate Services Partnership (NACSP). A panel of international climate services practitioners, including both government and academic, will provide their perspectives on the challenges and benefits of transboundary work, and session attendees will also be invited to share their transboundary experiences in a dialogue with the panel. Specific examples and lessons learned from sectoral and user engagement in the weather, water and climate enterprise will be highlighted - at both the continental and regional/boundary geographic scales - drawn from the portfolio of NACSP activities in Canada, Mexico, and the United States. Outcomes from the session will be used to foster a broader dialogue on the unique nature of cross-boundary collaborations, refine the priorities of NACSP going forward, and provide a framework for reporting these opportunities, obstacles, and evolving solutions in the climate services literature.