For more information, please visit our Frequently Asked Questions page. A filing fee is required for many immigration forms.These tips will help ensure we accept your application, petition, or request package for processing. Fill out the money order at the counter with a retail associate. Pay the dollar value of the money order plus the issuing fee. Students will need to complete a Form I-765 to USCIS after receiving the STEM OPT I-20 from ISSS. Instructions are found below. Children who regularly reside outside the United States may use Form N600K to apply for citizenship based on a US citizen parent. Check or money order mailed to USCIS as proof of payment. Abbreviations such as USDHS or DHS. 2.