521 CMR, § 37.8
Telephone Distribution: Where two or more telephones are provided in the same location, one shall be equipped with a Text telephone (TTY). The text telephone (TTY) shall be permanently affixed within the telephone enclosure. If an acoustic coupler is used, the telephone cord shall be at least 29 inches (29" = 737mm) long to allow connection of the text telephone (TTY) to the telephone receiver.
Exception: Where single interior public pay phones are provided in a stadium, or arena, a convention center, a hotel with a convention center, a covered mall, a public use area of a governmental building, in or adjacent to a hospital emergency room, recovery room or hospital waiting room, then it shall be equipped with a text telephone (TTY).
521 CMR, § 37.8