Many U.S. states have recognized the need for reliable data-driven information to plan and implement health-care policy. However, these needs have been difficult to meet because data are typically gathered and stored in separate data systems geared to support distinct programs or applications. Despite having huge amounts of health data, few states have been able to leverage the data in their holdings to link information across databases and produce useful analyses. Such data linkages typically allow information on a particular person from one data system to be linked with information about that same person from another system. With linked data, it is possible to make use of information that already exists to gain a better, more comprehensive understanding of health status, service use, market patterns, expenditures, and health outcomes. This chapter reviews linkage and other ways of combining data, approaches that have enormous potential to enhance the portfolio of health statistics we create, to provide perspective on the health of populations and the factors that influence the patterns we observe, and to enhance dissemination of health statistics that will improve the approaches we use to make improvements in health.