The original 1963 office was divided into four units overseen by Administrative Assistant Robert Keefe: Legislation, Department Relations, Press, and Services. Legislative staff was headed up by Robert Pitchell and under him Larry Conrad, with two legislative aides. With Bayh's assumption of the chairmanship of the Judiciary Committee's Subcommittee on Constitutional Amendments at the end of September 1963, Larry Conrad became his chief counsel in that role. Shortly after Pitchell's departure in early 1964, Clark F. Norton left his administrative and teaching positions at DePauw University to join the staff as legislative assistant. His "Executive Secretary" files, covering 1964-1969, indicate both his broader interests and his involvement in helping the office transition from a code-based filing system to a topical system. They have been kept separate within the Office Management Series and overlap to some extent with the Legislative Assistant's files in the Legislative Administration files of the Legislative Activity and Administration Series.

By 1969, AA Robert Keefe had restructured the office to resemble a typical Senate office, with departments for legislation, Indiana affairs, press, political matters, and office mamagement housed in separate rooms. Each department had key positions, a secretary, support staff, and interns.

By mid-1971, when Bayh was aspiring to a presidential nomination, his office included 40 Senate staff members, plus eleven to support to his chairmanships of the Judiciary Committee's Subcommittee on Constitutional Amendments (3) and Subcommittee to Investigate Juvenile Delinquency (8) and the Public Works Committee's Subcommittee on Roads (1); 23 on his political Bayh Committee, and 43 part-time employees and interns.

For the rest of his Senate tenure, his staff would range from 30 to 40, not including part-time employees and interns. Multi-tasking, based on areas of expertise would be a characteristic of staff throughout.