Q: Are locks permitted on patient room doors? Where can I locate the NFPA requirements for adding new hardware to patient room doors?
A: Section 18.104.22.168.2 of the 2012 Life Safety Code says locks are not permitted on patient sleeping room doors. Then, an exception to this standard says key-locking devices that restrict access to the room from the corridor and that are operable only by staff from the corridor side shall be permitted. Such devices shall not restrict egress from the room. What this means is you can lock the door to a patient sleeping room as long as the person on the inside of the room can open the door and get out.
However, before you think about adding deadbolt locks to existing doors, section 22.214.171.124.10.2 of the same code says you cannot have more than one lock or latch to operate the door. This means a deadbolt lock that is separate from the door latch set is not permitted because it takes two actions to operate the door: 1) Unlock the lock, and; 2) Turn the latch set handle. What you can have is a lock that automatically unlocks the door when the latch set handle is turned. These are also called hotel suite locks, because they are common in hotels. There is a deadbolt that is integrated with the latch set, and a person may unlock the door by simply grasping the latch set handle and turning.
If by chance the door in question is a fire-rated door, according to NFPA 80 you are permitted to make minor changes to the door in order to install new hardware, provided the hardware is listed for use on a fire rated door assembly.