Residency Start Date
Residency for a taxpayer who meets the 183-day substantial presence test begins the first day of the tax year the taxpayer was present in the U.S. and met the substantial presence test.
The start date of residency for taxpayers with green cards is the first day they were in the U.S. as lawful permanent residents. Typically, that is the day they received notice that their green card application was approved. Green card holders are resident aliens, even if they are not physically present in the U.S.
For foreign students and scholars who meet the substantial presence test and were also granted permanent residency, residency begins on the earlier of the two dates.