Here is the text from the INS site about fees
Paying Immigration-Related Fees After March 1, 2003
On March 1, 2003, the INS became a part of the
Department of Homeland Security. Immigration fees for
services and benefits previously payable to the
Immigration and Naturalization Service should no
longer be made out to INS. They should now be made
payable to "US Citizenship and Immigration Services"
(Note: Payments already submitted made payable to the
"Immigration and Naturalization Service" will continue
to be accepted.)