Access to the Supplemental Nutrition Assistance Program, or SNAP, and Temporary Assistance for Needy Families, or TANF programs has been restored.
The company says it was doing a test of its back-up system Saturday morning when the shutdown happened.
The Electronic Benefit Transfer, or EBT, system was restarted and, Xerox says, is at full functionality.
It affected 17 states where beneficiaries were having issues accessing benefits.
"We realize that access to these benefits is important to families in the states we serve. We continue to investigate the cause of the issue so we can take steps to ensure a similar interruption does not re-occur," Xerox said in a statement on Sunday.