Which of the following is NOT a mandatory guideline for the accreditation of a sleep lab?

The presence of an RPSGT (Registered Polysomnographic Technologist) on staff is a highly recommended standard for sleep labs, but it is not considered a mandatory guideline for accreditation. Accreditation organizations, such as the American Academy of Sleep Medicine (AASM), focus on ensuring that sleep facilities meet certain operational and clinical care guidelines, which include having a medical director and a board-certified sleep specialist present. These roles are critical for overseeing the lab's clinical practices and ensuring adherence to the standards of care.

In contrast, the requirement for a facility license is usually a regulatory necessity rather than an accreditation one. Each state may have specific laws governing the licensing of medical facilities, and while required for practice, it does not directly pertain to the caliber of care provided within the lab when it comes to accreditation standards. Thus, while having an RPSGT on staff contributes to the quality of care, it is not a stipulated requirement for accredited status, making it the correct answer to identify as not mandatory.