Social Security number for foster child

We have had one of our foster kiddos since June18...the day after he was born. I asked the caseworker back in November for a copy of his ss# and birth certificate. As of today, they still do not have his birth certificate and they do not know whether or not he has a ss#. We were needing his ss# to file our taxes. Is there any way that I can find out (other than the caseworker) if he has a ss# or not? In my past experience, I filled out the info for all my bio kids ss# at the hospital and it was then mailed to me. I am wondering if the parents filled out the form and the card was mailed to them. This caseworker is in no hurry to get the documents to me. Any help here would be very much appreciated! Teresa