Climate change is increasing the frequency and intensity of extreme rainfall events in many U.S. cities, driving up the risk of localized stormwater flooding. Stormwater has historically been managed only for water quality, since it can wash pollutants into waterbodies. Cities are now having to also manage stormwater for high volumes of water that flood streets and buildings and overwhelm stormwater systems. There is a regulatory gap in federal policies, technical support, and guidance since no single agency is focused on stormwater flooding. Cities will need to invest substantially in new stormwater infrastructure. Historically, these costs have fallen on ratepayers, which could put financial pressure on residents that are already cost burdened. As extreme rainfall continues to worsen, cities will need to combine infrastructure investments with additional supporting policies, including risk communication, improved planning, emergency response frameworks, and attention to flood insurance for residents and businesses.