Tax Return Filing Requirements
Am I required to file a tax return?
If you are in the US for 90 days or more during the year, or earn more than $3,000, then you have a tax return filing requirement. You need to file a return even if your earnings are all paid outisde the US or exempt under a tax treaty. Tax treaty benefits may be lost if not claimed on a timely filed return. Note that different filing requirements apply to business and investment income.