You may be a resident alien even if you had no green card at all during the year and it wasn't taken away by abandonment or the courts, if you met the "substantial presence" test in the US. These are complex rules and you should be sure you are still not considered a resident alien.
If you were not, then you need to make estimated payments on income earned income. The amount you need to pay in as estimated taxes depends upon many factors including, amount of income, tax treaties, etc.
We have tax treaties with many countries so that needs review as well. I certainly hope you get good tax advice during the year and at tax preparation time to make sure you do everything correctly.
Eric P. Rothenberg, P.C.
160 Gould Street-Suite 320
Needham, MA 02494-2300
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My colleague is correct - might be worth your time to simply give him a call and retain his services to get an estimate of your tax liability.
Evan A. Nielsen is licensed to practice law in California and handles federal tax matters throughout the U.S. The information provided here is for educational purposes only and is not intended as legal advice for a particular matter. This response does not create any attorney-client relationship with the author. For specific advice about your particular situation, please consult an attorney.