Abstract. The present article has a twofold objective. First, it proposes the Long-Term Care Coordination Index (LTC-CoIn), an analytical tool designed to systematically evaluate the scope of intergovernmental and intersectoral coordination mechanisms in long-term care (LTC) systems, applicable to any territorially complex country. Second, it applies this index to analyse the governance of the Spanish LTC system (SAAD) from its creation in 2006 to the present day. The methodology adopts a mixed-methods approach grounded in historical neo-institutionalism, combining documentary analysis and 16 semi-structured interviews with public decision-makers at the state, regional, and municipal levels, as well as sector experts, with the systematic ordinal scoring of the LTC-CoIn indicators through the triangulation of this qualitative evidence. The findings reveal a significant asymmetry between the two dimensions of coordination: while intergovernmental mechanisms show a moderate degree of development, intersectoral integration between health and social services remains an unresolved structural challenge, with critical deficits in integrated information systems, referral protocols, and interprofessional training. Beyond the Spanish case, the LTC-CoIn provides a replicable analytical framework for synchronic and diachronic comparative studies across different federal and multilevel systems