Daniel D. Ricciardi, MD, a board member of New York City's Health and Hospitals Corporation, has resigned after the agency began an inquiry into his role in securing a 10-year, $100 million contract for a Caribbean medical school where he has long had a paid position. Ricciardi was criticized by officials of New York-based medical schools for his role in securing the contract for the city's 11 public hospitals to provide clinical training to students from St. George's University School of Medicine in Grenada.