请问8老师，我妈是移民签证进的美国，进来就申请绿卡和ssn了，但都还没有寄到。家里老人急症病危，现在要回国。绿卡没收到之前离开美国travel，要办什么手续吗？
-No problem for her to travel in this case. When she entered US using the immigrant visa, the IO at the port of entry has endorsed her immigrant visa (i.e. put a stamp on the visa) which is equal to the temporary green card valid for one year. So, she can use this endorsed immigrant visa to travel.
我查了半天网站，没有这样的消息。谢谢
