The National Visa Center (NVC) provides case status information for green card requests submitted to U.S. Citizenship and Immigration Services. People can find a case status by calling the customer service line at (603) 334-0700 or by sending an email to NVCinquiry@state.gov.
When contacting the NVC by email, include the case number in the subject heading of the email. In the body of the email, include both the applicant's and petitioner's names and dates of birth. If the petition is employment based, the employer's name must also be included. As of May 2014, NVC case status information is not available online and NVC does not accept walk-ins.