Starting February 1, 2013, those who receive an immigrant visa package from a U.S. consulate or embassy abroad must pay both the Department of State application fee and the new $165 USCIS Immigrant Fee for each applicant.  The Fee can be paid online through the website. 

Failure to file the new fee will not impact permanent resident status however, the government will not issue a green card until the fee is paid.  Applicants who have not paid and desire proof of their lawful permanent resident status will still be able to obtain an I-551 stamp in their passport at a local USCIS office evidencing their status in the U.S. and their ability to work and remain in the country indefinitely.