Americans with disabilities are rarely considered a distinct group of health care users in the same way as are older Americans, children, racial and ethnic minorities, and others who are perceived to have different needs and access issues. Indeed, to some extent individuals with disabilities overlap with all these groups. But they also have distinct needs with material implications for the organization, delivery, and financing of health care services. Despite the disproportionate health care needs and expenditures of many--though not all--individuals with disabilities, the mainstream health services research community has largely neglected them. This article outlines the most pressing health service research issues in addressing the health care needs of individuals with disabilities.