This listing is not intended to be a comprehensive listing of all not-for-profit health agencies in the United States, nor does inclusion of any particular organization imply endorsement by the National Institutes of Health or the Department of Health and Human Services. Our intent is to provide information useful to individuals nationally, and for this reason we have not included many local groups that offer valuable assistance to patients and their families within a limited geographic area. Many of the organizations listed in this directory have information available to the public on the World Wide Web.