Does anyone have idea how can I determine my status in US either Resident alien or Non-Resident alien??? How long one should be in US to be considered Resident-Alien ?

haha dai dv parayra aayako ho?

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if you have a green card, you are a resident alien
if you dont then your a non-resident
has nothing to do with the amount of time you have been in the US

If you have a green card and you stayed in one state for a year or more you are resident alien if you stayed less than year you are non-resident, alien as far i know.

Not sure though..

If you have been here in United States for more than five years. given that you came to u.s w/ f-1 student and still legal, you are considered as a Resident-Alien.

f-1 student visa**

For Tax purposes,you may be considered resident alien if you are physically present in US for certain no. of days in a 3 yr period.

Here is the situation. I am in US for 2 and half years. I am qualified for substantial presence test. I came here in F-1 student visa. Graduated from one of US univ and have been working as a full time employee. I need to figure out about my residency stautus(either Resident alien or Non-resident alien) for tax return to use the right forms. it created the confusion to file ssn and medicare tax refund.
If anyone has alredy passed through this situation your information in this regard will be highly appreciated.

My present working status is OPT(f1)

if you are going to file for refund of social security and medicare taxes...which you should get since you are on OPT...you have to do the 1040NR form...too bad you won't be able to use the standard deduction or get tuition credit, so I would recommend you try both at first...if the NR return and SS refund amounts to more than the regualar 1040, go for that...otherwise just do the regular 1040.