FDA Commisioner James Goddard swears in 65 physicians on 10 July 1966 for various assignments in the Bureau of Medicine   including DESI, investigational drug and new drug review, and adverse reaction reporting.

The following year, 1966, the Bureau of Medicine introduced an Office and Division structure. The Office of New Drugs was responsible for reviewing all aspects of NDAs and investigational new drugs. The Office of Drug Surveillance reviewed adverse drug reaction reports and supplemental drug applications. Finally, the Office of Medical Review was responsible for regulatory actions. This latest reorganization also reflected the establishment of the Bureau of Veterinary Medicine in November 1965. Directed by M. Robert Clarkson, the Bureau was responsible for review of both veterinary drugs and devices. The human device program remained in the Bureau of Medicine until 1971. Sadusk resigned after overseeing the reorganization. Herbert Ley, who had been at both Harvard Medical School and George Washington University, succeeded Sadusk in September 1966. In 1967 the Bureau of Medicine replaced the Office of Drug Surveillance with the Office of Marketed Drugs, which was responsible for approval of supplemental applications. In addition, the Bureau established the Office of Medical Support to centralize a variety of functions in the Bureau, such as medical advertising and adverse reaction reporting.