The federal government has placed thousands of unaccompanied immigrant children in the homes of sponsors, but last year it couldn't account for nearly 1,500 of them. Steven Wagner, a top official with the Department of Health and Human Services, disclosed the number to a Senate subcommittee last month while discussing the state of the Office of Refugee Resettlement (ORR) that oversees the care of unaccompanied immigrant children. Wagner is the acting assistant secretary for the Administration for Children and Families. After a stay in an ORR shelter, the majority of children are sent to live with sponsors who have close ties to the children - typically a parent or close relative, Wagner said, though some end up living with "other-than-close relatives or non-relatives." Between October and December 2017, Wagner told the subcommittee, the ORR reached out to 7,635 unaccompanied children to check on them. But the ORR "was unable to determine with certainty the whereabouts of 1,475 children," Wagner testified. That's more than 19% of the children that were placed by the ORR. But Wagner said HHS is not responsible for the children. "ORR is not legally responsible for children after they are released from ORR care," Wagner said. Wagner's statement has received increased scrutiny a month after the Department of Homeland Security defended an agency policy that will result in more families being separated at the border.