Amid efforts to improve performance and constrain spending, federal agencies are being asked to expand the use of rigorous program evaluation in decision-making. In addition to performance data, indepth program evaluation studies are often needed for assessing program impact or designing improvements. Agencies can also use their evaluation resources to provide information needed for effective management and legislative oversight. GAO (Government Accountability Office) was asked to study federal agencies with mature evaluation capacity to examine (1) the criteria, policies, and procedures they use to determine programs to review, and (2) the influences on their choices. GAO reviewed agency materials and interviewed officials on evaluation planning in four agencies in three departments with extensive evaluation experience: Education, Health and Human Services (HHS), and Housing and Urban Development (HUD). HHS and HUD agreed with the description of how they plan evaluations. HHS noted that the optimal location of evaluation units will vary with the circumstances and purpose of evaluations. HUD felt the draft report did not emphasize enough the influence of the appropriations process. GAO has added text to note its influence on evaluation planning. Education provided technical comments. GAO makes no recommendations. Appendices include: (1) Comments from the Department of Health and Human Services; (2) Comments from the Department of Housing and Urban Development; and (3) GAO Contact and Staff Acknowledgments. A bibliography is included. (Contains 1 figure and 12 footnotes.)