The married, filing separately status does NOT require that both spouses file a return if one is below the threshold. When you file married, filing jointly, you need to report ALL income. When you file married, filing separately, the foreign spouse does not need to report foreign-sourced income, unless he has filed a return in the past. See Publication 519, U.S. Tax Guide for Aliens and Publication 501 (for Filing Requirements) for more information. Thank you very much for your clear answer and explanation , my last question is on the foreign earned income form there is a question asks“ for what period your family has lived with you in tax year?” we have lived together for long time , and married since second quarter of 2014 which means became a family officially , what date should I write down ? all tax year that we have lived together(but for a part of that not being a family officially) or just date after marriage registration ?does it have any conflict with the other forms and documents which show we are living together for long time? Thanks