NOTE: On March 23, 2012, minor revisions were made on pages 2 and 11 (see footnote 21).
CBO and the staff of the Joint Committee on Taxation (JCT) continue to expect that the Affordable Care Act (ACA)—the health care legislation enacted in March 2010—will lead to a small reduction in the number of people receiving employment-based health insurance. Some observers have expressed surprise that CBO and JCT have not expected a much larger reduction given the expanded eligibility for Medicaid and the subsidies for insurance coverage purchased through health insurance "exchanges" that will result from the ACA. CBO and JCT's estimates take account of those factors, but they also recognize that the legislation leaves in place some financial incentives and also creates new financial incentives for firms to offer and for many people to obtain health insurance coverage through their employers.
Despite the care and effort that CBO and JCT have devoted to modeling the health insurance system and the provisions of the ACA, there is clearly a tremendous amount of uncertainty about how employers and employees will respond to the set of opportunities and incentives under that legislation. In response to questions from Members of Congress, CBO and JCT have prepared an analysis showing how the effects of the ACA on health insurance coverage would differ under alternative assumptions about the behavior of employers.