The Personal Responsibility and Work Opportunity Reconciliation Act of 1996 greatly restricts the provision of many federal, state, and local public services to undocumented immigrants. These restrictions have prompted intense debates about the provision of free and discounted primary and preventive health care-services and have placed significant burdens on institutions that serve large undocumented immigrant populations. Intended to serve as a tool for reducing illegal immigration and protecting public resources, federal restrictions on undocumented immigrants' access to publicly financed health services unduly burden health care providers and threaten the public's health. These deleterious effects warrant the public health community's support of strategies designed to sustain provision of health services irrespective of immigration status.