No single U.S. counternarcotics strategy exists for the Andean region. In each country—Bolivia, Colombia, Ecuador, Peru, and Venezuela—the U.S. embassy’s mission strategic resource plan, developed in consultation with the country’s government, guides counternarcotics assistance provided by U.S. agencies. Department of State (State) officials told GAO that these plans incorporate high- level guidance from the Office of National Drug Control Policy’s (ONDCP) annual National Drug Control Strategy. In fiscal years 2006 through 2011, estimated allotments for counternarcotics assistance to the Andean countries by U.S. agencies—State, the U.S. Agency for International Development (USAID), the Department of Defense (DOD), and the Drug Enforcement Administration (DEA)—totaled about $5.2 billion. Total allotments declined for each country during this time period. State, USAID, and DEA reported meeting or exceeding most annual targets for key measures of their counternarcotics activities in the Andean countries since 2007. For instance, State reported assisting in the eradication of illicit crops, USAID reported promoting alternative development, and DEA reported disrupting drug trafficking organizations. In addition, State, USAID, and DEA complied with an ONDCP requirement that each agency’s Inspector General (IG) attest to the reliability of annual performance summary reports before submitting the reports to ONDCP. DOD reported tracking several performance measures, but DOD’s IG was unable to attest to the reliability of DOD’s reporting to ONDCP. As a result, ONDCP lacks assurance of the accuracy of information it receives from DOD and in turn reports to Congress. Why GAO Did This Study Hundreds of metric tons of cocaine flow annually from South America to the United States, threatening the security and well-being of U.S. citizens. South American cocaine production and trafficking is centered in the five countries in the Andean region. State, USAID, DOD, and DEA provide counternarcotics assistance to stem production and trafficking of narcotics in these countries. ONDCP oversees and coordinates this assistance. In this report, GAO (1) describes the U.S. strategic approaches to counter- narcotics assistance in the Andean countries; (2) identifies amounts allotted for such assistance by State, USAID, DOD, and DEA in fiscal years 2006 through 2011; and (3) reviews the agencies’ reporting on their performance. GAO reviewed agency and U.S. strategy documents, analyzed available agency data, and interviewed agency officials. What GAO Recommends The Secretary of Defense should ensure that DOD submits performance summary reports to ONDCP including the Inspector General’s attestation that the reported information is reliable to facilitate good management and oversight. DOD concurred with this recommendation.