National welfare reform is predicted to increase the number of homeless persons. This will affect the health care system by increasing the number of uninsured people and by multiplying the number of homeless persons seeking care in hospital emergency departments. Homeless persons have four major barriers to care: financial, bureaucratic, programmatic, and personal. The authors provide an overview of the homeless population, outline the barriers to health care for persons who are homeless, and highlight the major health care needs of this population. Finally, a community-based service delivery system developed by one agency in responding to the need of homeless persons is provided as a model of care.