This bill, titled the Water Infrastructure Subcontractor and Taxpayer Protection Act of 2025, amends the Water Infrastructure Finance and Innovation Act of 2014 (WIFIA) to introduce new requirements for payment and performance security on projects receiving federal assistance. It mandates that the Secretary or Administrator ensure construction projects funded under WIFIA have adequate security in place, aiming to protect subcontractors and taxpayers. This requirement can be met if applicable state or local law already demands payment and performance security, provided that the security amount is at least 50 percent of the total construction contract . If state or local laws do not meet this threshold or do not exist, the bill requires that federal bonding standards, similar to those outlined in 40 U.S.C. 3131(b), be applied. This measure is designed to ensure financial protection for work performed on federally supported water infrastructure projects.