IRS Publication 519: U.S. Tax Guide For Aliens

IRS Publication 519 is the U.S. Tax Guide For Aliens, a document the Internal Revenue Service (IRS) publishes that details the tax procedures for aliens, individuals that are not citizens of the United States.1 Not all aliens are subject to U.S. taxes. Resident aliens, those who have been in the country for a defined period, are subject to taxation on their worldwide income just as citizens are. Non-resident aliens are only taxed on income they earn within the U.S., as well as on certain types of international income.2