A US work permit is a document that permits a foreigner to the US to work within the country. This document is referred to as an Employment Authorization Document (EAD). US citizens and permanent residents do not need work permits to work in the US.
You will have to verify that you are eligible to apply for a work permit. To be eligible you need to fall within one of these categories: asylees and asylum seekers GO refugees; students seeking particular types of employment; applicants to adjust to permanent residence status; people in or applying for temporary protected status; fiances of American citizens; and dependents of foreign government officials.
Fill out form I-765. This form can be obtained from the USCIS website or you can get a copy free of charge from a USCIS center near you. Follow the instructions carefully and write legibly.
Attach the following to your filled out I-765 form: -your I-94 departure record -your application fee which is currently $340. This is subject to change so check the USCIS website to verify the amount of the fees. - Your two identical color photographs of yourself taken within 30 days of the filing of the application -supporting documentation proving eligibility depending on what category you fall under. The documentation is specified on form I-765 under the instructions section.
Submit your form and all attached documentation to the USCIS . Instructions on where to file your application are also listed under the instructions section of form I-765
You should hear from the USCIS within 90 days. If your application is rejected, they will send a letter explaining why. If approved, your work permit will be mailed to you.