A brief by Mathematica Policy Research, Inc. examined the experiences of individuals with severe mental illnesses (SMI) in the Medicaid Buy-In program.  The Medicaid Buy-In program allows states to use Medicaid to cover workers with disabilities whose income and assets would typically make them ineligible for the program. 

From the report:　

The Medicaid Buy-In program is a key component of the federal effort to make it easier for people with disabilities to work without losing health benefits. Authorized by the Balanced Budget Act of 1997 (BBA) and the Ticket to Work and Work Incentives Improvement Act of 1999 (Ticket Act), the Buy-In program allows states to expand Medicaid coverage to workers with disabilities whose income and assets would ordinarily make them ineligible for Medicaid. To be eligible for the Buy-In program, an individual must have a disability (as defined by the Social Security Administration, SSA) and earned income, and must meet other financial eligibility requirements established by states.

Full Report: How Are the Experiences of Individuals with Severe Mental Illness Different from Those of Other Medicaid Buy-In Participants? (PDF | 379 KB)  

Mathematica Policy Research, Inc. (2010). How are the experiences of individuals with sever mental illness different from those of other Medicaid buy-in participants?.  Liu, S. and Croake, S.