At a time when U.S. military forces and their equipment are in high demand, effective management of the Department of Defense's (DOD) inventory is critical to ensure that the warfighter has the right items at the right time. The Air Force is the largest contributor to DOD's total on-hand inventory on the basis of inventory value. Under the statutory authority of the Comptroller General to conduct evaluations on his own initiative, GAO determined the extent to which (1) the Air Force's on-order and on-hand inventory reflect the amount of inventory needed to support required inventory levels from fiscal years 2002 through 2005, and (2) the Air Force had shortages in its inventory needed to support required levels during this period. To address these objectives GAO analyzed Air Force secondary inventory data (spare parts such as engines and guided missiles) from fiscal years 2002 through 2005. GAO recommends that the Air Force take four specific actions to strengthen the accountability and improve the management of its secondary inventory. DOD generally concurred with our recommendations. However, we do not believe DOD's planned actions fully respond to two of the recommendations in our report. ; GAO Report to Congressional Committees. The original document contains color images.