You can file as “head of household” for 2012 if you are unmarried at the end of 2012 and you maintained a household for your child, parent, or other qualifying relative. You must be a U.S. citizen or resident (18.1) for the entire year. Tax rates are lower for a head of household than for a person filing as single (1.2) and the standard deduction is higher (Chapter 13). If you are married but for the last half of 2012 you lived apart from your spouse, you may be treated as unmarried and able to qualify for head of household tax rates and standard deduction, which are more favorable than those for a married person filing separately; see Test 1 below.
You must meet both of these tests to qualify as a head of household: