Noncitizen Eligibility for Federal Public Assistance: Policy Overview and Trends

"The extent to which residents of the United States who are not U.S. citizens should be eligible for federally funded public aid has been a contentious issue for more than a decade. This issue meets at the intersection of two major policy areas: immigration policy and welfare policy. The eligibility of noncitizens for public assistance programs is based on a complex set of rules that are determined largely by the type of noncitizen in question and the nature of services being offered. Over the past 16 years, Congress has enacted significant changes in U.S. immigration policy and welfare policy. Congress has exercised oversight of revisions made by the 1996 welfare reform law (the Personal Responsibility and Work Opportunity Reconciliation Act, P.L. 104-193)— including the rules governing noncitizen eligibility for public assistance that it established—and
legislation covering programs with major restrictions on noncitizens’ eligibility (e.g., food stamps/SNAP, Medicaid)."
http://www.fas.org/sgp/crs/misc/RL33809.pdf