Abstract : Acquiring military equipment is big business. The value of the current portfolio of major weapon systems is about $1.5 trillion. Managing such a huge portfolio requires access to an enormous amount of acquisition data, including the cost and schedule of weapon systems (both procurement and operations), information about how they perform technically, contracts and contractor performance, and program decision memoranda. The Office of the Under Secretary of Defense for Acquisition, Technology and Logistics (OUSD[AT&L]) and those working for it need access to such data to track acquisition program and system performance and ensure that progress is being made toward such institutional goals as achieving efficiency in defense acquisition and delivering weapon systems to the field on time and on budget. A range of organizations need access to the data for different purposes (e.g., management, oversight, analysis, administrative). Such organizations include various offices of the Department of Defense (DoD), federally funded research and development centers, universityaffiliated research centers, and a host of support contractors. But getting access to the data to carry out the analyses requested by DoD is not always easy, or in some cases even possible. At times, the data carry dissemination restrictions that limit their distribution. In other cases, proprietary information is the property of a commercial firm and may not be released without that firm s explicit permission. The Office of the Secretary of Defense (OSD) asked the RAND National Defense Research Institute to identify the problems and challenges associated with sharing unclassified information and to investigate the role of policies and practices associated with such sharing. This report details the issues associated with gaining access to what is called Controlled Unclassified Information (CUI).