This issue brief from the Kaiser Family Foundation explores the impact of health reform proposals on state variation in structuring Medicaid programs. 

From the executive summary:

Leading health reform proposals in both the House and the Senate include a Medicaid expansion to help eliminate state variation in the current program and to broaden health coverage for more low-income Americans (including childless adults who are now generally barred from Medicaid coverage). Because Medicaid is a program that is jointly administered and financed by states and the federal government, changes to Medicaid will have direct impact on states. While health reform legislation could have many implications for states, this brief highlights some of the potential benefits and costs to the states associated with Medicaid expansion in the reform proposals.

Full report: http://www.kff.org/healthreform/8005.cfm

The Kaiser Family Foundation. (2009). Health reform issues: state financing and Medicaid.