This legislation aims to address the significant underutilization of federal office space by imposing strict in-person work and occupancy requirements on Federal agencies. Within 120 days of enactment, each agency head must modify policies to require that not less than 80 percent of employees work in-person Monday through Friday each week. Additionally, agencies must ensure that not less than 60 percent of the usable square feet of their office space is occupied by employees. These requirements are based on findings from the Government Accountability Office, the Public Buildings Reform Board, and the GSA Office of Inspector General, which highlight widespread underutilization, billions in wasted spending, and potential health risks in underoccupied federal buildings. An exception to the 60% occupancy rule allows agencies with insufficient staff to submit an occupancy plan within one year, detailing how they will achieve the target, potentially by accommodating employees from other Federal agencies. Failure to comply with these in-person work and occupancy mandates by the specified deadlines will trigger significant consequences. For properties owned or controlled by a non-compliant agency, the property must be sold. If the property is leased, the agency or the General Services Administration must either terminate the lease early, if provisions allow, or be prohibited from re-signing the lease upon its expiration. The Comptroller General is also required to submit a report to Congress within one year regarding the implementation of these new requirements.