Since 2010, the State Higher Education Executive Officers Association (SHEEO) has periodically administered the "Strong Foundations" survey, which documents the content, structure, and effective use of state postsecondary student unit record systems (PSURSs). This report highlights the results of the fourth administration of the survey, conducted in 2018. This report includes: (1) a description of the status of postsecondary data systems; (2) an analysis of which educational sectors are covered by these systems; (3) detailed information about demographic and financial aid data elements contained in PSURSs; (4) an analysis of states' abilities to calculate performance metrics; (5) a description of the growing prevalence of linkages between PSURSs and other administrative data sets; (6) an analysis of privacy and security practices; and (7) a discussion of the effective use of PSURSs and their chief value to states. This year's report highlights new information regarding the types of information states collect from various educational sectors (two-year, four-year, public, and private). This report includes states' self-assessments of their ability to calculate metrics regarding access, progression, completion, cost, and post-collegiate outcomes. The report includes a detailed discussion of the pervasiveness of PSURSs' use of benchmark privacy and security practices. These include privacy and security processes (i.e., data governance and physical security), standards (Family Educational Rights and Privacy Act (FERPA), state statute, etc.), and practices (destroying data, employee training). [Cover title varies: "Strong Foundations 2018: The State of Postsecondary Data Systems."]