Me and my husband separted in about May 2006 and have lived apart ever since. We have recon. around March of this year and moved back in together. I have filed head of household because I have the kids with me and he has filed single. How should we file this year since we are back together?

" around March of this year and moved back in together. I have filed head of household because I have the kids with me and he has filed single."---->As both you and your spouse filed a separate return( as single/HOH), you generally can change to a joint return any time within 3 years from the due date of the separate returns. This does not include any extensions. If you qualify the rule, then you can file your amended Federal and state tax returns to change your filing status to MFJ.Your filing status is determined in large part by your marital status on the last day of the year. You should use Form 1040X, Amended U.S. Individual Income Tax Return, to correct a previously filed Form 1040, Form 1040A, or Form 1040EZ.