Summary: Significant changes in legislation and policy have allowed women to fly combat aircraft, serve on combat ships, and serve in more combat-related jobs. As of September 1998, 90 percent of the military's 1,425,000 positions were open to women. GAO found that a large percentage of military women continue to work in the areas of health care, administration, personnel, and supply occupations. However, data suggest that military women are beginning to enter more nontraditional fields, such as aviation, surface warfare, air traffic control, and field artillery. Although most military occupations and career fields are open to women, GAO identified two institutional barriers that limit the number of women going into these occupations. First, because of military policies, some units are closed to women even though the units may include occupations that are open to women. For example, the Navy limits the number of enlisted women in its nuclear training program because women cannot serve on submarines. Another barrier is the test used to match enlisted personnel to occupations, which contains sections that are based on exposure to a subject instead of aptitude. For example, women tend not to test well on knowledge of automotive components, systems, tools, and repairs because they often have had little or no experience with these subjects.