U.S. citizens are taxed on their worldwide income. They must figure gain or loss on the sale of foreign real property. If the foreign property is a residence, the home sale exclusion may apply. Note: If foreign taxes are paid on the sale, this may trigger a deduction or credit for those taxes.
On Form 1040X, you may file an amended return within a three-year period to claim a refund or correct a mistake made on an original or previously amended return.