CBO’s analyses of the distribution of household income and federal taxes are based on administrative tax data from the Internal Revenue Service’s Statistics of Income (SOI) and on household survey data from the Census Bureau’s Current Population Survey (CPS). Those two data sources contain complementary information. The SOI data contain detailed income information for those who file taxes each year but lack information for those who do not file taxes; the data also lack information about nontaxable sources of income. The CPS data contain information about a wide range of nontaxable sources of income for all U.S. households, regardless of whether they file tax returns in a given year. By statistically combining the information from those two sources, CBO creates a comprehensive database of income sources for all U.S. households to serve as the foundation for its distributional analyses. This presentation provides an overview of the algorithm that CBO uses to statistically match the SOI and CPS data, and it provides some summary statistics on the characteristics of nonfiling tax units. Presentation by Kevin Perese, an analyst in CBO's Tax Analysis Division, at a Washington Center for Equitable Growth workshop on distributional national accounts.