Dr. Miller joined the Food and Drug Administration in 1979 and served in a number of posts. He was the medical reviewer for the first genetically engineered drugs evaluated by the FDA and was instrumental in the rapid licensing of human insulin and human growth hormone. Thereafter, he was a special assistant to the FDA commissioner, with responsibility for biotechnology issues, and from 1989 to 1993 was the founding director of the FDA's Office of Biotechnology. During his government service, Miller participated frequently on various expert and policy panels as a representative of the FDA or the U.S. government. While a government official, Miller was the recipient of numerous awards and citations. After leaving government service, Miller became the Robert Wesson Fellow in Scientific Philosophy and Public Policy at the Hoover Institution, 1994–96.