The satellite-based Global Positioning System GPS provides positioning, navigation, and timing PNT data to users worldwide. GPS is an essential U.S. national security asset and a key component of economic growth, national infrastructure, and transportation safety. The Department of Defense DODspecifically, the Air Forcedevelops and operates the GPS system, which consists of three segments space, which comprises a constellation of PNT satellites orbiting the earth ground control, which primarily consists of running software in facilities that operate the satellites as well as monitoring and correcting signal data and receivers, which help civil and military users employ GPS signals to determine their location, among other uses. In the past several years, GAO has issued a number of reports related to GPS programs, including the most recent detailed assessment of the next generation operational control system OCX and development of military GPS user equipment MGUE.1 GAO assessed the OCX, GPS III satellites, and MGUE programs in our annual assessments of selected DOD weapon systems.2 The National Defense Authorization Act for Fiscal Year 2016 contained a provision that the Air Force provide quarterly reports to GAO on the next generation GPS acquisition programs.3 The Act also contained a provision that GAO brief congressional defense committees on the first report, and at GAOs discretion, for subsequent quarterly reports. The Air Force delivered the first quarterly report to GAO on April 22, 2016. GAO assessed the report and briefed congressional committees in June 2016 on 1 the extent to which the Air Forces report provided transparent information on the GPS acquisition programs quarterly progress, risks, and short-term acquisition plans and 2 observations for improving future Air Force quarterly reports on GPS.4 This report summarizes information provided at the briefing.