This guidebook, a comprehensive national directory of Federal offices, programs, and facilities supporting K-12 education in mathematics and science, was designed to inform educators and the public about Federally-supported resources in these subjects and to increase access to them. It contains information about Federal offices and programs at the national and regional levels and also lists state-by-state contacts for many of these resources. Sixteen Federal agencies collaborated with the Eisenhower National Clearinghouse (ENC) to produce this publication. Section One contains general information about the 16 agencies and highlights their involvement in mathematics and science education, acquaints the reader with agency-specific background information, and lists its administrative offices for mathematics and science education. Section Two features nationwide agency-sponsored mathematics and science programs for elementary and secondary education. Each program entry includes the program name, a brief program description, and contact information. Section Three lists, by state and region, those agency resources available at the local level. Although this Guidebook does not list all federally-funded education programs, it does provide contacts that can supply additional information. (JRH)