April 20, 2012 Updated: April 20, 2012 UPDATE: USCIS National Customer Service Center by Kellie N. Lego Tweet Share Share April 20, 2012, USCIS National Customer Service Center (NCSC) will not be available to receive calls about individual cases from 12:30PM – 4:30PM ET. The NCSC will be available to answer general immigration questions during that time.