Preserve Science in Policymaking Act of 2019 This bill limits the authority of the President or a federal agency or officer to terminate an advisory committee before the end of its charter. The following must first occur: (1) the termination must be authorized by law or unanimously approved by the Chief Data Officer, Chief Evaluation Officer, and Chief Information Officer of the relevant agency; (2) not later than 60 days before the advisory committee is scheduled to be terminated, the relevant agency shall submit to Congress a notification of such termination; and (3) such agency must provide for a public notice and comment period.