The National Estuary Program (NEP) is the U.S. Environmental Protection Agencys (EPA) flagship national watershed program. The NEP is authorized and funded through SC320 of the Clean Water Act (CWA). The NEP uses locally-based collaborative decision-making to prioritize and protect coastal and estuarine resources in 28 different locations in the continental U.S. and Puerto Rico. This report summarizes NEP accomplishments documented during EPAs Implementation Reviews (IRs) of the 28 NEPs during 2004-2006. The EPA conducts IRs of the 28 programs included in the NEP to determine progress implementing their respective Comprehensive Conservation and Management Plans (CCMPs), and continued eligibility for funding under SC320 of the CWA. EPA has established and maintained an IR for each NEP every three years that carefully assesses the accomplishments and challenges facing each NEP. The comprehensive IR includes a detailed report submitted by each NEP, an on-site visit by a team of EPA headquarters and regional staff, and a final determination of eligibility for continued funding. As a result of the IR process, recommendations for management changes are provided, as needed, and then revisited as part of the NEPs next IR. These recommendations have resulted in significant and important changes in program management, and are the basis for reporting program accomplishments. This report also discusses the new Program Evaluation (PE) Guidance released by EPA in September 2007 which is being used for the 2008-2010 IRs.