According to the USCIS:
If the federal government shutdown prevented you from contesting a Tentative Nonconfirmation (TNC), you will be allowed additional time to contact the Social Security Administration (SSA) or Department of Homeland Security (DHS). If your TNC was referred between September 17, 2013 and September 30, 2013, and you were not able to resolve the mismatch due to the federal government shutdown, you should:
- Add 12 federal business days to the date printed on the ‘Referral Letter’ or ‘Referral Date Confirmation’ that your employer provided you after you contested the TNC. Federal business days are Monday through Friday and do not include federal holidays.
- Contact SSA or DHS by the new date to resolve your TNC.
If you received a Final Non-Confirmation (FNC) because you could not contact DHS or SSA during the federal government shutdown, or because you could not contact DHS or SSA in the first ten days after the government reopened, please contact your employer and request that the employer re-enter your query. For more information about contesting your TNC or FNC, please refer to Employee section of the E-Verify website.