If you need to stay in the U.S. longer, request an extension well before your visa expires. An "overstay" can result in a denial of a future visa.
Employment Authorization Document (EAD)
If you are a foreign visitor such as an international student, researcher, or refugee, you might be able to work temporarily in the United States with an Employment Authorization Document (EAD) work permit, which can be issued to certain nonimmigrant visa holders. You will need the actual physical EAD card before you can start working. The card is your proof to an employer that you are authorized to work in the U.S.
Travel Documents for Foreign Residents Returning to the U.S.
If you have a Permanent Resident Card (Green Card), or are a foreign citizen living in the U.S., you may need additional documents to return to the U.S. after traveling abroad. Obtain these necessary documents from United States Citizenship and Immigration Services (USCIS) before your trip: