This report focuses on information sharing in the federal effort to secure US ports against a potential terrorist attack. The Coast Guard has lead responsibility in coordinating maritime information sharing efforts. The Coast Guard has established area maritime security committees--forums that involve federal and nonfederal officials who identify and address risks in a port. The Coast Guard and other agencies have sought to further enhance information sharing and port security operations by establishing interagency operational centers--command centers that tie together the efforts of federal and nonfederal participants. This testimony is a summary and update to an April 2005 report, and identifies barriers that have hindered information sharing.