Md. Code, Business Occupations and Professions § 4–507

(a) A barbershop may not employ at the same time more than three apprentice barbers for each master barber employed.

(b) A barbershop may have a separate shampoo area.

(c) The Board may not require a barbershop to have a minimum number of sinks.

(d) (1) An apprentice barber under complete and constant supervision of a master barber may assist the master barber in starting or completing an operation. The master barber or barbershop may charge the usual fees for the operation.

(2) A fee may not be charged for an operation performed completely by an apprentice barber.