He began practicing pediatrics in 1976 in Enosburg Falls, Vermont. From 1987 – 1991 Dr. Mayer was a National Cancer Institute Epidemiology Fellow at Columbia University School of Public Health in New York City, researching the molecular biology of childhood cancer. He was also a pediatrician with Columbia’s General Pediatric Group Practice. Dr. Mayer established Rainbow Pediatrics in Middlebury, VT, where he continues to practice primary care pediatrics. He is an Instructor in Pediatrics at the University of Vermont School of Medicine and a J-term adjunct faculty for Middlebury College pre-med students. He is the author of Life in a Jar.