Dr. JoAnn Johnson graduated from the University of Tennessee, Memphis Medical School, in 1977. She completed a rotating internship at Erlanger Hospital in Chattanooga, Tennessee in 1978 and her pediatric residency in Birmingham, Alabama in 1981. She was board certified in 1988 and recently completed her maintenance of certification in 2010.

Dr. Johnson practiced for four years in Birmingham and Anniston, Alabama before establishing her own business. In 1986, Dr. Johnson opened her first pediatric practice in Athens, Alabama, known as Athens Pediatrics. She practiced in Athens for twenty-three years and moved her practice to Huntsville, Alabama in 2009, now known as Over the Rainbow Pediatrics.