Resident Alien
Definition: A resident alien is treated as a United States person for US tax purposes and is a non-US person who meets either the green card test, or the substantial presence test for the calendar year (January 1 – December 31). A person that does not meet either test is a nonresident alien. There are rules for determining the Residency Starting and Ending Dates for aliens. In some cases aliens are allowed to make elections that take precedence over the green card test and the substantial