This is defined by U.S. tax regulations as an international person who has been physically present in the United States for the amount of time required to be treated as a resident alien for tax purposes. The status is determined based on the substantial presence test and the visa type of the individual. Resident aliens for tax purposes are taxed in the same manner as a U.S. citizen. A resident alien for tax purposes must report ALL income from ALL sources, regardless of whether from the U.S. or foreign payors.