Dr. Yonker attended the College of Osteopathic Medicine and Surgery in Des Moines, Iowa where he received his D.O degree. Dr. Yonker's internship was completed in Philadelphia, Pennsylvania at the Parkview Hospital. Dr. Yonkers' residency in Internal Medicine was completed at the Albert Einstein Medical Center-Northern Division in Philadelphia, Pennsylvania. His fellowship in Rheumatology was completed at the University of Florida located in Gainesville, Florida. In 1984, Dr. Yonker joined the Sarasota Arthritis Center.