The Bureau of the Census has been conducting interviews for the Survey of Income and Program Participation (SIPP) since October 1983. The SIPP is a national survey and is designed to provide improved information on income and participation in government programs for the noninstitutionalized United States population. Person and household characteristics that may influence income and program participation are also available from the SIPP. This information is vital for improving the capability of federal agencies to formulate and evaluate their policies and programs in the areas of income and social welfare.