It is widely understood that both small firm workers and self-employed individuals constitute a disproportionate share of the uninsured. It is somewhat surprising, however, that little information or analysis is available on the substantial overlap between these populations as it pertains to health insurance coverage.

This is an important area for investigation because "self-employed" businesses are very numerous and employ many small firm workers. Self-employed businesses, as defined by the Internal revenue code, are comprised of firms organized as sole-proprietorships, partnerships, and S-corporations. Firms headed by sole proprietors and partners are of particular interest because workers in these unincorporated businesses are less likely to have employment-based coverage and more likely to be uninsured than workers in an incorporated firm of the same size.

In this overview, we assess the impact of tax policies and market rules on insurance coverage rates and examine the implications for health insurance coverage expansions programs for these workers.