The "Terrorist Watchlist Data Accuracy and Transparency Act" aims to significantly improve the accuracy of the Department of Homeland Security's (DHS) terrorism screening information. It mandates that prior to submitting an initial nomination for an individual to the federal terrorist watchlist or other terrorism databases, DHS must conduct a quality assurance review . This review ensures that all information contained in the nomination is entirely free from error before it is sent to the Federal Bureau of Investigation's Terrorist Screening Center and the National Counterterrorism Center. Beyond initial nominations, the bill establishes a robust auditing framework. Annually, DHS is required to review all nominations of United States persons to these databases, verifying data accuracy and adherence to the Watchlisting Advisory Council's criteria. Furthermore, a monthly random audit program will be implemented to periodically review all departmental nominations, ensuring ongoing data integrity and compliance for all individuals. Should any review or audit identify errors or non-compliance, DHS must notify the FBI's Terrorist Screening Center and the National Counterterrorism Center within 24 hours, requesting appropriate corrections or retractions. If a requested correction or retraction is not effectuated within 30 days, the Secretary of Homeland Security must promptly consult with the respective Director. The bill also mandates an annual report to Congress detailing the number of identities referred for corrections or retractions, disaggregated by U.S. and non-U.S. persons, and the outcomes of these referrals.