Tax exemption and Roth IRA eligibility

[Guest cindylee]

I am doing research on H1b visa. I am considered "resident alien" for tax purpose although I am not green card holder. According to the tax treaty between my home country and US, my income for conducting research (my only income) is exempted from federal tax. My employer does provide 401(k).

Can anyone please tell me if I am eligible to open Roth IRA? Thanks a lot!