This paper documents the increased role of pass-through entities and the associated decline in use of the taxable corporate form since the Tax Reform Act of 1986 (TRA86) and discusses implications for the design of tax policy. We show how significant reductions in the corporate tax rate, absent changes in the personal tax rate, would reverse the organizational form incentives that have existed since TRA86. If the loss in revenue from a rate reduction is offset by a broadening of the tax base, most business entities, comprising most business income, will face an overall increase in their tax burden.