On May 26, KFF released a study conducted by the Urban Institute for the Kaiser Commission on Medicaid and the Uninsured that offers a state-by-state analysis of the impact of the expansion of Medicaid outlined in the national health care reform law.  The report examines the impact of the expansion on Medicaid enrollment, the number of uninsured, and state and federal Medicaid costs.  Nationally, the study projects that the federal government will cover $443.5 billion of the cost of the Medicaid expansion, or 95.4 percent of the total cost, while the states will fund $21.2 billion.  The study also estimates that the expansion will result in 15.9 million more individuals enrolling in Medicaid than otherwise would have by 2019, and 11 million fewer uninsured.

From the report:

Today there is a great deal of variation across states in terms of Medicaid coverage, the uninsured, state fiscal capacity, leadership and priorities. These variations make it impossible to know how each state individually will respond to the new health reform law. There are a range of implementation scenarios that will impact the number of people who participate or sign up for coverage and these participation rates are directly related to the estimates of coverage and cost for health reform. Since it is impossible to predict the behavior of each state, this analysis examines two participation rate scenarios that are applied uniformly across states; however, we recognize that some states may implement reform to achieve coverage levels above expectations and others may be slower to implement reform or face implementation barriers that result in lower coverage levels.

Full report:  Medicaid Coverage and Spending in Health Reform: National and State‐by‐State Results for Adults at or Below 133% FPL (PDF | 1.01 MB) 

Kaiser Family Foundation. (2010). Medicaid coverage and spending in health reform: national and state‐by‐state results for adults at or below 133% FPL.