28 CFR Part 35 Nondiscrimination on the Basis of Disability in State and Local Government Services (1991 ADA Title II Regulations)

(8) A public entity shall not impose or apply eligibility criteria that screen out or tend to screen out an individual with a disability or any class of individuals with disabilities from fully and equally enjoying any service, program, or activity, unless such criteria can be shown to be necessary for the provision of the service, program, or activity being offered.