This bill aims to reduce the Federal Government's reliance and expenditures on outdated information technology (IT) systems by requiring agencies to systematically address their legacy infrastructure. It establishes a framework for identifying, planning for, and ultimately modernizing or retiring these older systems across federal agencies. A core provision requires each agency's Chief Information Officer to compile an inventory of all legacy IT systems used by their agency within one year of enactment, and every five years thereafter. The Director of the Office of Management and Budget (OMB) will issue guidance detailing the specific information to be included for each system, such as its purpose, connection to other systems, annual operating costs, and planned updates or disposal dates. This inventory must be made available to Congress, the Comptroller General, or agency inspectors general upon request, ensuring transparency. Furthermore, agencies must develop comprehensive modernization plans every five years, starting two years after the bill's enactment. These plans, integrated into their existing information resource management strategies, must identify prioritized legacy systems for updates, modernization, retirement, or disposal, outlining the steps the agency intends to take over a five-year period. The OMB Director may also require additional information, such as estimated costs and funding sources, and the impact of modernization on connected non-legacy systems. The OMB Director, in coordination with the Administrator of the Office of Electronic Government, is tasked with issuing detailed guidance for the Act's implementation, including criteria for defining legacy IT systems and templates for inventories and modernization plans. Within three years, the Comptroller General will submit a report to Congress assessing the Act's implementation and its integration with other federal IT modernization initiatives and programs. The bill includes provisions to protect sensitive information and explicitly exempts national security systems from its requirements. It also prohibits the transfer of legacy IT systems or equipment to the Chinese Communist Party or entities controlled by the People's Republic of China. Importantly, the Act does not authorize new funds for its implementation and is set to sunset six years after its enactment.