The Defense Department is in the process of assuming the task of conducting background checks on government personnel from the Office of Personnel Management’s National Background Investigations Bureau. Once the changeover is complete in October, the Pentagon will be responsible for approving security clearances for the roughly 4.2 million federal employees and government contractors. Of those, 3.6 million work for DoD as employees or contractors. The responsibility moved to the Pentagon as a result of provision of the 2017 defense-spending bill, and an April decree by President Trump. The newly established Defense Counterintelligence and Security agency will take the lead in conducting the checks.