The Americans with Disabilities Act (ADA) is a civil rights statute, giving rights to everyone, but is structured to require people claiming its protections to have a characteristic, “disability.” This structure presents an apparent paradox: how can a statute accord both civil rights to all and special rights to some? This contribution argues that the paradox can be dissolved by understanding discrimination “based on” disability as treating people unfairly because of a characteristic they have, in two critically different forms. One form is individual: the failure to accommodate mental or physical differences to enable individuals to work successfully, participate in public services, or experience public accommodations as others do. Another form is general: the failure to adjust the world of built structures or created policies that exclude people with disabilities. Recognizing this difference between exclusions rooted in the failure to accommodate and exclusions rooted in the failure to modify is critical to the disability anti-discrimination project. So is the recognition that there are other forms of unjust exclusion that disability anti-discrimination law does not address.