Before starting his own practice Joel Milliner worked as a medical director and physician.  In his role as a physician, he reviewed patient lab work, ensured preventative screening occurs, treated patients with a wide variety of maladies, and managed chronic care patients. As a medical director for Joel was responsible for ordering and reviewing diagnostic tests,  signing of on Nurse Practitioner patient notes, and providing urgent care. 

Following years in private practice, Milliner was made Chief Physician of the Boston Medical Group. There his practice focused on the needs of men, including performing penile u/s and biothesiometry and patient education to treat ED, as well as checking and monitoring testosterone levels. At Corizon Correctional Healthcare, Joel Milliner ensured that chronic care patients with HIV, DM, Hepatitis C, HTN, and obesity met control goals. He also oversaw and adjusted medication for inmates and conducted didactic sessions with Nurse Practitioners and Physician Assistants to improve care.