Prof MacKay offers general adult and paediatric ear, nose, throat and head and neck assessment and surgical services. He completed his medical degree at the University of NSW in 1998, graduating with honours. His Fellowship in Otolaryngology and Head and Neck Surgery was completed in 2006. In 2007 he completed a Fellowship in Airway Reconstruction Surgery for Snoring and Obstructive Sleep Apnoea. This Fellowship also involved further training in Head and Neck and Laryngology (Voice).

In 2008 Prof MacKay started the Illawarra Multidisciplinary Sleep Apnoea Team Meeting and acts as the Chair, holding monthly patient reviews with various other specialists and allied health staff. He also has been an invited speaker and chair of Snoring and Sleep Apnoea Panels nationally and internationally. He is one of the most recognisable surgeons for sleep apnoea and snoring after his fellowship mentor, Dr Samuel Robinson.

He is actively involved in teaching as both Professor and Examiner at the University of Wollongong Medical School. He is a member of the Australasian Sleep Association and its clinical committee. He is the current vice president of the International Surgical Sleep Society and is a chief investigator on NHMRC and Garnett- Passe Funded Research Projects.