I am on L1B-Individual visa, expires on Nov-11. My employer will apply for an extension in Aug. Can I travel outside US in Sept?

Sure, if the visa stamp in your passport hasn't expired, you can travel. QUESTION: Did you ask the company's immigration lawyer this question? If so, did he/she say anything different? If not, why didn't you contact him/her first?

Hello, If you have travel plans in September you should request Premium Processing when you file for your extension. That way you should have a decision before you travel.

If your employer is filing your L-1B extension next month, it may not be advisable to travel abroad while the case is still pending with USCIS. If you have an L-1 visa which is valid until Nov. 2015, you may be able to travel overseas once your L-1B petition has been approved, or you may have to apply for a new L-1 visa at a U.S. consulate abroad. You should discuss this with your employer or the attorney who is filing the L-1B extension on your behalf.