I'm from Brazil, married with an American Citizen. I live in Brazil. We don't live together for a long time and he doesn't help me with anything. He still uses my name to have tax deduction because I don't work in the US. Is that correct?
Thanks.

If you are still married, he can still file jointly with you.

Now, it is likely he is signing your name on the tax return. THAT is illegal if he is doing it witholut your consent. A letter to the IRS stating that the return has not been signed by you could cause your husband some REAL problems with the IRS.

Is that your intent?