Originally Posted by
AtlantaTaxExpert
There is a retroactive tax clause that requires you pay the taxes for the first two years if you stay beyond the original two-year J-1 tour. It is contained in the technical explanation of te U.S.-India Tax Treaty; extract below.
If a professor or teacher remains in the host State for more than the specified two-year
period, he may be subject to tax in that State, under its law, for the entire period of his presence.
It COULD be an issue when you apply for the green card, as the USCIS asks the IRS to review the tax returns for all green card candidates.