The U.S. Office of Special Counsel (OSC) received a whistleblower disclosure concerning employees at U.S. Customs and Border Protection’s (CBP) National Targeting Center–Cargo, in Herndon, Virginia and the National Targeting Center– Passenger, in Reston, Virginia. The whistleblower alleged that employees in both locations regularly claim administratively uncontrollable overtime (AUO), but fail to perform duties that qualify for AUO. OSC referred this allegation to DHS Acting Secretary Rand Beers. The Department subsequently requested our assistance with this allegation and several other AUO-related allegations from other DHS components. We assembled a taskforce of auditors, program analysts, investigators, and attorneys to review these allegations. Federal regulations allow agencies to pay AUO annually to employees in positions that require substantial amounts of irregular or occasional overtime work and in which the hours of duty cannot be controlled administratively. The National Targeting Center did not have sufficient AUO documentation to allow us to specifically identify a violation of law, rule, or regulation. However, most of the tasks employees performed during AUO hours appear to have been administratively controllable.