The status of women varies strikingly across major federal agencies. In 1987, for instance, women comprised 66 percent of all white-collar employees in the Department of Health and Human Services (HHS) but only 23 percent in the Department of Transportation (DOT). They made up 28 percent of employees at grade GS 13 or above in the Department of Education, but only 6 percent at National Acronautics and Space Administration (NASA). The difference in mean grades between men and women was as low as 1.9 grades in the Veterans Administration (VA) and as high as 4.4 grades in the NASA. Does this mean that HHS, Education, and the VA have much to teach DOT and NASA about how to achieve sexual equality.? Or do structural differences largely predetermine the relative status of men and women in each agency? I argue that differences in agency mission, as reflected in the occupational mix of the forces, are responsible for most of the interagency variation in the status of women. The number of employees in each white-collar occupation predicts the sexual composition of an agencys force and midlle-management staff and the relative grade levels of male and female employees. This single variable explains interagency differences better than previous multivariate models, and shows that simple measures of sexual inequality tell us little about how successfully federal agencies are utilizing the potential of their female employees. Previous Research Kranz (1977) gave the fullest description of interagency variation in utilization of women and minorities. With the Civil Service Reform Act of 1978, Congress required all agencies to compute a variety of underrepresentation indexes to allow comparisons of the utilization of women and minorities over time and across agencies. Searches for the causes of interagency differences have focused on agencies' goals and timetables as indications of effort expended (Rosenbloom, 1975); on agency size and growth as measures of opportunities to increase equality (Nachmias and Rosenbloom, 1973; Grabosky and Rosenbloom, 1975; Kellough, 1990); on agency constituencies as a measure of political pressures for equality Borjas, 1982); on union strength as a possible extra-agency obstacle to equality (Kellough, 1990); and on the percentage of the agency force in lower grade levels, in clerical or blue-collar occupations, or in the Southwest region as measures of the supply of certain types of workers (Grabosky and Rosenbloom, 1975, Kelough, 1990). Hypothesis As in the general society, the federal civil service strongly differentiates men's work from work. In 1967, 49 percent of the men and 42 percent of the women in federal white-collar employment labored in occupations where at least 95 percent of their coworkers were of their same sex (Lewis and Emmert, 1986). Although sexual segregation of occupations is declining both in the general economy (Bianchi and Rytina, 1986; Blau and Hendricks, 1979) and in the federal service (Lewis and Emmert, 1986), most occupations remain strongly identified with one sex; in 1987, 55 percent of federal white-collar women (or men) would have needed to change occupations for the sexes to have identical occupational distributions (Lewis, 1990). Because mens pays much better than women's work, even when skill and educational requirements of the jobs and characteristics of the workers are very similar (e.g., England et al, 1982; Ferber and Lowry, 1976; Gunderson, 1976; Jusenius, 1977; Snyder and Hudis, 1979; Stevenson, 1975; Treiman and Hartman, 1981), sexual segregation of occupations has a crucial impact on the pay of men and women. In the federal service, for instance, each additional percentage of an occupation's workers who were male in 1982 was associated with in additional $80 in annual salary, even for workers of the same sex, race, seniority, and educational level Lewis and Emmert, 1986). …