<prompt> Human: Im trying to obtain financial aid from my university. Recently, they sent me an email saying that my dad had filed as head of household even though he is married. They are wanting to know why he filed like that. Could he file the way he did since my mom is still not a legal resident and he claimed my younger siblings?  <response>: Only under certain circumstances: IRS Publication 17 IRS.gov Namely, if the IRS considers him unmarried matches ANY of the reasons under the Marital Status section and can file head of household matches ALL of the reasons under the Head of Household section. 