Extension procedures are identical to the procedures followed in getting the initial visa, except that less documentation is
generally required. However, the best practice is to fully document the extension request with all of the documents submitted with the initial petition, as USCIS will probably not have the file on site.
Working While Your Extension
Petition Is Pending
If you file your petition for an extension of O, P, or R status before your authorized stay expires, you are automatically permitted to continue working for up to 240 days while you are waiting for a decision. If, however, your authorized stay expires after you have filed for an extension but before you receive an approval, and more than 240 days go by without getting a decision on your extension petition, continued employment is not authorized and you must stop working.
If you leave the U. S. after your extension has been approved, but the underlying visa has expired, you must get a new visa stamp issued at a consulate. Read Section D, above. The procedures for consular extensions are identical. ■