The challenges associated with securing U.S. Department of Defense (DoD) information systems have grown as the department's information infrastructure has become more complex and interconnected. At the same time, the potential negative consequences associated with cyber intrusions have become more severe. Are current information assurance (IA) policies and procedures sufficient to address this growing threat, and are they able to address vulnerability issues associated with highly networked information systems? The current IA certification and accreditation (C&A) process focuses on individual, discrete systems or components of larger, aggregated information systems and networks that are colocated or operate on the same platform (such as a Navy ship). An examination of current policy shows that a new approach is needed to effectively extend the IA C&A process to aggregations of information systems and improve the security of DoD information systems. A number of recommendations are put forth to improve current IA policy and to enable the IA C&A of aggregations of DoD information systems that reside on a common platform.