Why GAO Did This Study. In 2011, the Army began a major undertaking to modernize its tactical network to improve communication and provide needed information to soldiers on the battlefield. The Army has identified the network as its number one modernization priority requiring approximately $3 billion per year indefinitely. NIEs provide semi-annual assessments of newly developed systems. Given the importance of the network, GAO was asked to examine elements of the process the Army is using to acquire network capabilities. This report examines (1) the results of the NIEs conducted to date and the extent to which the Army has procured and fielded network solutions, and (2) Army actions to enhance the NIE process. To conduct this work, GAO analyzed key documents, observed testing activities, and interviewed acquisition and testing officials. What GAO Recommends. To improve outcomes for the Army s network modernization strategy, GAO recommends that the Secretary of Defense direct the Army to (1) require successful developmental testing before moving to operational testing at an NIE, (2) correct issues identified during testing at NIEs prior to buying and fielding systems, (3) provide results to industry on Army s efforts to rapidly acquire emerging capabilities, and (4) pursue additional opportunities for collaboration with the test community on the NIEs. DOD agreed with the recommendations to varying degrees, but generally did not offer specific actions to address them. GAO believes all recommendations remain valid.