Across OECD countries, healthcare organizations increasingly rely on inter-organizational collaboration (IOC). Yet, systematic insight into the relations across different healthcare sectors is lacking. The aim of this explorative study is twofold. First, to understand how IOC differs across healthcare sectors with regards to characteristics, motives and the role of health policy. Second, to understand which potential effects healthcare executives consider prior to the establishment of the collaborations. For this purpose, a survey was conducted among a representative panel of Dutch healthcare executives from medium-sized or large healthcare organizations. Almost half (n = 344, 48%) of the invited executives participated. Our results suggest that differences in policy changes and institutional developments across healthcare sectors affect the scope and type of IOC: hospitals generally operate in small horizontal collaborations, while larger and more complex mixed and non-horizontal collaborations are more present among nursing homes, disability care and mental care organizations. We find that before establishing IOCs, most healthcare executives conduct a self-assessment including the potential effects of the collaboration. The extensive overview of policy developments, collaboration types and intended outcomes presented in our study offers a useful starting point for a more in-depth assessment of the effectiveness of collaborations among healthcare organizations.