Monitored Anesthesia Care (MAC) is performed by a qualified anesthesia provider solely purposed to administer and monitor the patient's anesthetic care and managing any attendant airway, hemodynamic or physiologic compromise.
MAC anesthesia is commonly mistaken for minimal or moderate sedation (or even deep sedation) but MAC can be any depth of sedation from just monitoring and resuscitating a critically ill patient during a diagnostic or therapeutic procedure to minimal or moderate or deep sedation or even conversion to general anesthesia.
"Whatever the patient can tolerate balanced with whatever it takes to get through the procedure."
By definition, moderate sedation requires the patient to respond purposefully to verbal commands. However, quite commonly, during many procedures, there is a need for the patient to not respond during parts of the procedure that are more stimulating or painful. So a common expectation (for many MAC cases) is a period of general anesthesia (commonly supporting the airway but less frequently requiring airway instrumentation).
So, "we will just do a MAC", does not necessarily mean minimal sedation/awake patient. However sometimes it does mean a minimally sedated/awake patient, particularly if that is all the patient can safely tolerate.