This bill requires the Department of Housing and Urban Development (HUD) to significantly enhance its oversight of financial payments. It mandates the Secretary of HUD to conduct a compliant improper payment assessment for both project-based and tenant-based assistance programs by December 1, 2027. This assessment must be included in the agency's fiscal year 2027 financial report, with a detailed plan and timeline developed for testing and reporting improper payment estimates in key rental assistance programs. Furthermore, the legislation establishes mechanisms for identifying and addressing potential fraud. HUD must notify its Inspector General (IG) within 60 days if housing assistance payments or recipients, or Community Development Block Grant amounts or sub-recipients, increase by more than 100 percent in a specific geographic area within a single year. Annually, the IG is then required to audit programs or areas showing a 400 percent increase over five years to ensure compliance and detect fraudulent activity. The IG also plays a crucial role in pre-validating HUD's assessment methodology and conducting a separate fraud risk assessment for rental assistance, including analyzing data and identifying barriers to utilizing the "Do Not Pay" database.