Dr. Mackles practiced hospital-based neonatal medicine in Florida for over twenty-two years after completing a Pediatric Residency at Lenox Hill Hospital in New York City, and a Fellowship in Neonatology at The Cornell University Medical Center. In addition to receiving an MBA from Nova Southeastern University, Dr. Mackles obtained his license as a Healthcare Risk Manager through studies at the University of South Florida.

Dr. Mackles was elected to the Board of Directors of The Florida Society for Healthcare Risk Management and Patient Safety for a two-year term from 2006-2008, and again for a one-year term from 2014-2015. Dr. Mackles has served as an instructor with the University of Florida Distance Education Risk Management and Patient Safety Program and also participated as a faculty member of the University of South Florida Risk Management Licensure Program.  In addition, Dr. Mackles is the author of multiple online continuing education courses on patient safety topics for The Sullivan Group. Dr. Mackles now devotes full-time to risk management and patient safety issues.