Mark Hadley began working in Respiratory Therapy in 1992 at City Hospital in Martinsburg, West Virginia. After moving to California in 1994, Hadley worked at Northridge Hospital and the Sherman Oaks Burn Center.

In 2000, he was employed at John’s Hopkins in the Neonatal Intensive Care Unit and was attending college to earn a bachelor’s degree.

In 2001, he returned to California and was hired at Lompoc Valley Medical Center as a respiratory therapist. In 2003, he became the Director of Respiratory Therapy, which in 2010 became the Cardiopulmonary Services Department.