This bill modifies the line of succession for Department of Homeland Security (DHS) officials. Specifically, the bill provides that the Under Secretary for Management shall serve as the Acting Secretary if the Secretary, Deputy Secretary, and Associate Secretary are not available to exercise the duties of the Office of the Secretary. Current law makes no reference to the Associate Secretary. The bill contains further requirements, including that an official must have served in DHS for at least 90 days prior to the designation to be within the line of succession to serve as acting head of a DHS component.