South China Sea Freedom of Navigation Act This bill extends updates of the Department of Defense Freedom of Navigation Report under the Freedom of Navigation Operations (FONOPS) program through December 31, 2025. The bill requires (1) the report to be submitted on a biannual basis, and (2) each report to document the types and locations of excessive maritime claims that the Armed Forces of the United States have challenged in the previous six months in order to preserve the rights, freedoms, and uses of the sea and airspace guaranteed to all countries by international law. The bill modifies elements of the report to include a summary of each excessive maritime claim challenged jointly with international partners and allies.