The "Duplication Scoring Act of 2026" establishes a new requirement for the Comptroller General of the United States to analyze specific legislation for potential duplication with existing federal programs. This measure aims to prevent the creation of redundant government offices, programs, or initiatives by identifying overlaps early in the legislative process. Under this Act, the Comptroller General must determine if a covered bill or joint resolution creates a new duplicative or overlapping feature that mirrors an existing duplicative or overlapping feature previously identified in GAO reports. If such a risk is found, the Comptroller General is required to identify the new feature, its location within the bill, and the relevant GAO report detailing the existing overlap. This information will then be submitted to the Director of the Congressional Budget Office and the committee that reported the bill, and also published on the Government Accountability Office's website. The Director of the Congressional Budget Office may include this duplication assessment as a supplement to the bill's cost estimate, ensuring that potential redundancies are highlighted during legislative review. The Act is designed to take effect either 60 days after a specific update to an Office of Management and Budget website or at the start of a new Congress, whichever occurs first.