This bill, titled the "Preventing Violence Against Female Inmates Act of 2025," introduces new requirements for housing prisoners within the federal system. It mandates that the Bureau of Prisons use an individual's biological sex when making housing determinations, defining it based on reproductive potential, sex chromosomes, hormones, gonads, and nonambiguous internal and external genitalia present at birth. Federal detention facilities are generally prohibited from co-locating persons of different biological sexes, with a narrow exception allowing for temporary, non-overnight co-location. The legislation also extends these requirements to state prisons by impacting their eligibility for federal funding. Beginning in the first fiscal year after enactment, states must certify to the Attorney General that they prohibit co-locating individuals of different biological sexes in their detention facilities. This certification is necessary to receive funds under Section 501 of title I of the Omnibus Crime Control and Safe Streets Act of 1968, with states also permitted only temporary, non-overnight co-location exceptions.