I am a Chinese citizen and lived in the Netherlands before coming to the US. I hold a J-1 visa and do some research projects at Northhwestern University.
According the the Netherland-US treaty, I had a tax-exemption for the first two years.
Recently, as I prepared the tax return form, the results showed that I would need repay the tax that would be exempt, because I will remain in the US for more than two-year time period. This was due to my program being extended.
I checked the Netherlands-US treaty, and found that they do have a rule about tax retroactivity if I stay in US exceeding 2 years.
Meanwhile, I found there are exceptions, one which states that "If the visit exceeds two years, the first-mentioned State may tax the individual under its national law for the entire period of the visit, unless in a particular case the competent authorities of the States agree otherwise."
I do not know whether my situation is this kind of exceptions, or how could apply it. How can I get this clarified?