I am a USA citizen but live and work in a foreign country, should I enter a USA mailing address (my brothers address ) or my foreign living address in my tax return.

[dnhingorani]

 if I enter my brothers  USA address as my mailing address, my return does not have any indication of my foreign address and does not state that I live outside the usa.

[Opus 17]

You should use the address where you want the IRS to send you official mail, and your refund check (if you are due a refund and there is problem with the bank deposit.)

Your tax return address does not have to match your residence.