Currently, the valid address for sending Form G-639, Freedom of Information Act/Privacy Act Request, is the following:
National Records Center (NRC)
P.O. Box 648010
Lee’s Summit, MO 64064-8010
The contact information may change from time to time, so before submitting Form G-639 please visit the official website page https://www.uscis.gov/g-639 or call National Customer Service Center for the most current information.