ATC Hiring Reform Act of 2019 This bill requires the Federal Aviation Administration (FAA) to give preferential consideration to employment applications of air traffic control specialists (1) who have completed air traffic controller training and graduated from an institution participating in the Collegiate Training Initiative program, or (2) who are veterans. The bill also requires (1) the FAA to submit semi-annual reports to Congress on the hiring and training of air traffic controllers, (2) the FAA to give preferential consideration to applicants who gained air traffic control experience at a National Guard facility, and (3) the Inspector General of the Department of Transportation to conduct a review that assesses the assumptions and methodologies used by the FAA in developing the air traffic controller pre-employment test.