Dr. Gainor completed his pre-pharmacy studies at the University of Michigan, and then received his Bachelor of Science from the University of Pittsburgh School of Pharmacy. After completing a one-year residency in hospital pharmacy, Dr. Gainor entered the graduate program at the University of Pittsburgh School of Pharmacy, a Master of Science and Doctor of Philosophy degrees. He then entered the University of Pittsburgh School of Law, graduating with a Juris Doctor degree in 1975. He was admitted to practice in the U.S. Federal Courts in 1975, and in 1979 he was admitted to practice before the United States Supreme Court.

Dr. Gainor maintained a private law practice in Pittsburgh, Pennsylvania for over fifteen years, with an emphasis on cases related to health care. He is currently legal counsel to the Pennsylvania Pharmaceutical Association, an Assistant Professor at the University of Pittsburgh, and an Adjunct Professor at the University of Pittsburgh, and an Adjunct Professor at the University of Arizona. Dr. Gainor has presented over 500 lectures throughout the United States on health related topics including malpractice, risk management, bioethics, and managed care.