This topic discussed residency status of foreign students and scholars for filing U.S. taxes.
Aliens are considered residents for tax purposes if they hold a green card at any time during the calendar year. Nonresident aliens meet the substantial presence test if they were present in the U.S. more than 183 days. Dual status aliens are resident aliens and nonresident aliens at different times in the same tax year.
Exemptions from counting days toward the substantial presence are granted for:
For taxpayers who meet the 183-day substantial presence test, the start date of residency for tax purposes is the first day the person was in the U.S. in the tax year in which the substantial presence test was met.
Nonresident aliens may still be treated as residents for tax purposes if they are married to U.S. citizens.