Data sharing is a key component of cross-sector collaborations to address the health and social needs of people and reduce inequities. However, achieving efficient exchange of information across partners from health care, public health, and social services can be challenging. Several states use integrated data systems to link administrative individual-level data across multiple health and human services programs to better understand and address the health and social needs of those who use such services. This paper examines established integrated data systems to identify facilitators and barriers to successful cross-sector data-sharing. Among our key findings are that understanding privacy laws, leadership buy-in, and the type of organizational culture that values data are important for data-sharing efforts. We also found that establishing legal frameworks and governance structures and promoting data literacy are promising strategies to foster such conditions. Finally, we found that in data-sharing efforts, people skills are at least as important as technical skills. However, people and communities whose data are being collected and shared are often absent from discussions and decisionmaking about cross-sector data collaborations. Organizations considering cross-sector data sharing must recognize the importance of building trusting relationships with all relevant stakeholders, including program participants and the public.