The Rehabilitation Research and Training Center on Measuring Rehabilitation Outcomes and Effectiveness along with academic, professional, provider, accreditor, and other organizations sponsored a 2-day State of the Science of Post-Acute Rehabilitation Symposium in February 2007. The aim of this symposium was to serve as a catalyst for expanded research on post-acute care (PAC) rehabilitation so that health policy is founded on a solid evidence base. The goals were to (1) describe the state of our knowledge regarding utilization, organization, and outcomes of postacute rehabilitation settings, (2) identify methodologic and measurement challenges to conducting research, (3) foster the exchange of ideas among researchers, policymakers, industry representatives, funding agency staff, consumers, and advocacy groups, and (4) identify critical issues related to setting, delivery, payment, and effectiveness of rehabilitation services. Plenary presentation and state-of-the-science summaries were organized around four themes: (1) the need for improved measurement of key rehabilitation variables and methods to collect and analyze this information, (2) factors that influence access to postacute rehabilitation care, (3) similarities and differences in quality and quantity of services across PAC settings, and (4) effectiveness of postacute rehabilitation services. The full set of symposium articles, including recommendations for future research, appear in Archives of Physical Medicine and Rehabilitation.