OECD Health DataCovers health-related data for member OECD nations. It's available through the ZSR database page.
Agency for HealthCare Research and Quality from the U.S. Department of Health & Human Services
The Congressional Budget Office (CBO)
FEDSTATS find statistics at the national or state leve on a broad range of topics
Health Interactive DataFrom the Centers for Disease Control
National Center for Health Statistics from the Centers for Disease Control
National Center for Health Statistics from the Center for Disease Control and Prevention
National Vital Statistics System go here for data on births, deaths, infant mortality, etc.
Statistical Resources from the U.S. Department of Health and Human Services
State Health Facts provided by the Kaiser Family Foundation
Statistics from WomensHealth.gov a division of the U.S. Department of Health & Human Services