Guide to the ADA Standards

Are access key, card, or code entry systems permitted in elevators?

Yes, but fixed features of such systems must comply as operable parts. For example, card readers must be located within accessible reach ranges. Non-fixed portions, including keys and access cards issued to users, are not required to comply. (Where use of stairs between levels served by an elevator is unrestricted, use of the elevator should not be restricted to key holders.)