Summary: GAO discussed the Department of Defense's (DOD) implementation of revolving door legislation, which required former DOD employees to report their employment with and compensation from defense contractors. GAO found that: (1) only 30 percent of former DOD employees who were required to report actually reported their employment with DOD contractors; (2) about 5,800 of the 12,000 former DOD employees with security clearances worked for contractors with $10 million or more in defense contracts; (3) DOD interpretation of the reporting criteria resulted in a significant number of former employees being exempted from the requirements; (4) about 34 percent of the 200 post-1986 reports it reviewed did not meet additional DOD requirements; (5) DOD reinvestigated certain cases for possible conflicts of interest; (6) defense contractors were not uniformly reporting compensation to former DOD personnel, but about 85 percent of the companies complied with the requirements; (7) it was unable to assess the impact of prohibited employment because DOD inconsistently interpreted and implemented the requirements; and (8) DOD failure to properly apply the employment prohibition could result in more DOD procurement employees gaining post-DOD employment with defense contractors than Congress intended.