Green card holders are considered to be U.S. persons for tax purposes by the U.S. government and are, therefore, required to file and pay tax returns. If you are a green card holder who has moved abroad or returned back to your home country and never officially given up your green card, then you are still subject to U.S. income taxation. Only those who have formally surrendered their green card, or have had it revoked or abandoned by a final determination, are not obligated to pay and file their tax returns.