Dr. Hewlett received an M.D. from the University of Wisconsin, Madison Wisconsin and is Board certified in Internal Medicine and Infectious Diseases. He completed an internal medicine residency at Harlem Hospital Center – Columbia University College of Physicians & Surgeons in New York City. He then served for an additional year as Chief Medical Resident at Harlem Hospital Center. Following internal Medicine training, Dr. Hewlett completed a two year clinical and research fellowship in Infectious Diseases at Montefiore Medical Center and Albert Einstein Affiliated Hospitals in the Bronx, New York.

Following completion of Post-graduate medical training, Dr. Hewlett served as the Chief of the Infectious Disease Division at Lincoln Medical & Mental Health Center in the Bronx, New York and Associate Professor of Clinical Medicine at New York Medical College for nine years prior to joining the pharmaceutical industry in 1996. Throughout his 23 year career in the Pharmaceutical industry he simultaneously served on the voluntary medical staff as an Infectious Disease consultant at Lawrence Hospital Bronxville, New York and as an Infectious Diseases consultant and Co-Chair of Infection Control at Calvary Hospital in the Bronx, NY.

Since retirement from the pharmaceutical Industry in 2019, Dr. Hewlett has served as Medical Director at the Westchester County Department of Health Clinics where he has medical oversight of Immunization clinics, Tuberculosis services, Sexually Transmitted Infection clinics and HIV prevention Clinics. Since July 2021, Dr. Hewlett has served  as Principal Investigator on a Health Literacy Grant from  the U.S Department of Health & Human Services

Dr. Hewlett is a Fellow of the American College of Physicians, The Infectious Disease Society of America and the New York Academy of Medicine. He is the recipient of an Infectious Diseases of America Citation Award in 2021. He currently serves as Vice Chair of the Infectious Disease Society of America Foundation Board of Directors, the Board of Directors for Calvary Hospital and is a member of the National Medical Association Task force on the COVID Vaccines. He is married to Janice Marie Chance-Hewlett B.S.N. R.N. and they have four adult children and four grandchildren.