Hi,

After reading of all the answers I think I found the answer, but want to be sure.

I'm a Postdoctorand on a J-1 viza in a status of a research scholar. I'm for 1-2 years in the US and get money from the USA. I'm a German citizen and a nonresident in US.
I pointed out in the 8233 Form the Article 20(4). Is it good, or should I better use 20(1)?
So, I don't have to pay any federal taxes, but still state taxes. Right?

And at the end of the year I should fill out the 14... form and tell there that I use a tax treaty US/Germany.

Thank you!

From Publication 901: Tax treaties:
Germany
A professor or teacher who is a resident of Germany and who is temporarily in the United States to engage in advanced study or research or teaching at an accredited educational institution or institution engaged in research for the public benefit is exempt from U.S. tax on income received for such study, research, or teaching for a maximum of 2 years from the date of arrival in the United States.

The exemption does not apply to income from research carried on mainly for the private benefit of any person rather than in the public interest. The exemption does not apply if, during the preceding period, the benefit described in paragraph (2), (3), or (4) of Article 20 of the treaty, pertaining to students, was claimed.

You will file nonresident tax return and Form 8843 showing your income, then showing the exempt income, and no taxable income.

I just talked to a German tax expert, and she said that after claiming the Germany-US treaty, you now have to file a German tax return and pay taxes there on your US income. Thought you might be interested to find that out, even if it is bad news... better knowing now than having them come after you in a couple years with a big fine.