We've been separated and living in different cities for few months now and never applied for a divorce or any other legal separation. I have received Green Card through husband when he applied through his work permit (H1B to GC). It is 5 years since we got the Green Cards, and I would like to apply for citizenship. Is there anything that we would need to do jointly or can I apply myself totally separate from him? Do I need to know of any potential problems and issues, if I choose to file for citizenship totally separately? Can I do it in the first place at all? Since I got the GC through him, do we need to stay married and file jointly for citizenship? If I can file totally independently, do I need to provide any information about the spouse, and marriage? It looks like the application form requires spouse's Alien no., what if I cannot get it from him? Since we are not officially divorced, what is the status I can state on the application form for citizenship? I do not have any tax returns for last 4 years; I will be filing married but separate tax returns for 2005. He would have filed jointly till 2004 and I do not have access to them. Can I get copies directly from IRS? Anyone in similar situation or with similar experience, I would really appreciate any help you can provide. Thank you.