Hello,
I was employed and paid taxes in India (2004-2006) before moving to study in Singapore. Having recently graduated, I intend to spend two years to the USA on an international fellowship and J1-visa starting August 2011. By August 2011, I would have paid taxes for one year in Singapore. I will be grateful if someone can provide me definitive answers to the following.

a) Is my income from international fellowship taxable in the USA? My employer is supplementing the fellowship (by ~20%). Can I assume that only that 20% of the income will be taxable in the USA? I will be moving with two dependents (wife and 2 year child).

b) I hold Indian passport and permanent address in India. Therefore, I should be considered resident of India for tax purpose and not of Singapore. Right?

c) Given my situation, what taxes (please let me know the % of income) does the employer has to withhold according to law? Out of these taxes, which taxes can I claim back?

Thanks

Every one on J1 is exempt from residency for two years. They must file nonresident tax return.
Research fellow on J-1 from India are exempt from paying federal income tax for two years. Your U.S. Tax Return: U.S. Tax Filing Requirements for Non-Residents (http://taxipay.blogspot.com/2008/03/us-tax-filing-requirements-for-non.html)

This is from IRS publication 901. Tax treaties.
"An individual is exempt from U.S. tax on income received for teaching or research if he or she:
Is a resident of India immediately before visiting the United States, and
Is in the United States to teach or engage in research at an accredited university or other recognized educational institution in the United States for a period not longer than 2 years.
If the individual's visit to the United States exceeds 2 years, the exemption is lost for the entire visit.
This exemption does not apply to income from research carried on mainly for the private benefit of any person rather than in the public interest. "