From 1984 to 1987 he was counsel for the House committees on intelligence and foreign affairs. He served as a staff attorney on the joint US House–Senate committee investigation of the Iran-Contra affair as an assistant to Congressman Bill Broomfield (R-MI). Books and news articles have said that he was one of the principal authors of a controversial minority report issued at the conclusion of the joint committee's investigation, which "defended President Reagan by claiming it was 'unconstitutional for Congress to pass laws intruding' on the 'commander in chief.'" but in his opening remarks as he testified under subpoena before the House Judiciary Committee, Addington said that he had left the committee's service before the minority report was written and had no role in it.