G-5 domestics who are in the United States less than 183 days in their first year working in the US are considered non-resident aliens for Federal income tax purposes and will file a Form 1040NR for the first year of employment.
The IRS has established a new procedure for calculating the amount of income tax to withhold from the wages of G-5 domestics classified as nonresident aliens. A new chart has been created that requires additional income to be added to wages for calculating the tax withholding amount only. In addition, a new withholding table for nonresident aliens must be used in conjunction with the new tax withholding tables used to figure withholding tax on other employees. The result of the new procedure is that withholding for nonresident alien G-5 domestics in 2010 is over 250% more than it was in 2009. To learn more, review section 9 of IRS publication 15 (Circular E) Employer's Tax Guide for 2010. You can download it from the IRS website using the following link: http://www.irs.gov/pub/irs-pdf/p15.pdf?portlet=3.
A G-5 domestic is a non-immigrant visa established to allow certain diplomatic personnel, including eligible staff of Non-Governmental Organizations (NGOs) such as the United Nations, World Bank, International Monetary Fund, etc., to have their family's domestic servants accompany them for postings within the United States. The G-5 domestic is subject to the same taxation as any other wage earner in the United States, and their sponsor (a G-4 visa holder) must report and pay all required Federal and state employment taxes.