The Kelsey Smith Act amends federal telecommunications law to require mobile service providers and internet-based voice service providers to immediately disclose a phone's location to law enforcement and emergency responders in urgent situations. Specifically, providers must share location data when law enforcement requests it for a phone that placed a 911 call in the past 48 hours or when there is reasonable suspicion that the device belongs to someone in an emergency involving risk of death or serious injury. The law requires law enforcement agencies to keep records of all location requests, documenting the officer's name, the reason for the request, and how it meets the emergency criteria. The bill protects telecommunications companies from legal liability for providing this information and does not prevent states from enacting stronger privacy protections. The legislation applies to commercial mobile services and internet-based phone services.