Working for Supranational Organizations such as the UN, EC, WHO or WB has many advantages - your tax status being one of them. However, this benefit significantly complicates your U.S. tax reporting. Due to the increased level of tax complexity we advise having your taxes handled by a qualified professional.
Many of our clients work for Supranational Organizations. Hence we are very familiar with the issues they face (such as proper exclusion of Social Security tax, reporting income from the Form 1099 as wages, calculation of the non-taxable portion of pension benefits, etc).
Deduction for the resident country Social Security contributions is only available only for a select list of countries with which US has Social Security treaties. Unfortunately there is no such treaty between the US and the UN - hence your contribution to the UN social security system are not deductible.
For U.S. citizens, compensation received for services performed as an employee of an international organization is includible in their gross income and is reportable on their U.S. federal income tax returns.
Compensation received by a U.S. citizen for services performed within the United States as an employee of a foreign government is subject to self-employment tax.
Work performed outside the United States is not subject to self-employment tax.