The size and adequacy of the federal workforce for carrying out scientific, technical, engineering, and mathematics (STEM) activities are ongoing concerns in many policy circles. Experts both inside and outside of government have voiced fears that this workforce is aging and may soon face a dwindling labor pool, a problem that could be compounded by skill shortages in key areas and growing numbers of non-U.S. citizens obtaining STEM degrees in the United States. The authors assess the condition of this workforce, based on the best available data, while focusing on three main areas: trends in the U.S. STEM workforce overall that might affect the federal STEM workforce, workforce-shaping activities in the federal STEM workforce, and legislative and programmatic mechanisms for influencing that workforce. (Contains 93 footnotes and 12 figures.) [For associated report summary, see ED502752.]