@lfvc2000 , if you did not have much foreign earned income AND you did not take any steps to give up your IL residency then for IL purposes you would still be "significantly" connected to IL -- your home is IL, your family is in IL and you intended to return to IL after your sojourn abroad. Additionally most of your income ( interest , dividend, pension etc. ) are essentially passive and generally will be sourced to IL. And you clearly recognized IL as a source state by estimated tax payment. Hence I see no real advantage in NOT filing as MFJ ( Married Filing Joint ) for IL taxes. Now if you had a lot of foreign active income ( wages/ self-employment etc. ) then there could be a benefit in keeping that foreign income out of IL by not filing an IL return and allowing the Interest and dividend income ( probably jointly owned by you and your spouse) and therefore the estimated tax payments to be recognized by your spouse ONLY.
Does that help or do you need more --- in which case please provide answers to -- (a) quantum of foreign earned/self-employment income; (b) which country; (c) when did you arrive in foreign country and when did you arrive back in the USA; (d) did you try and exclude the foreign income from US taxes etc. etc.; (e) did you pay any foreign taxes on the income ( if )
