Which marital status should I check?

If you are not legally divorced, you have the choice of Married Filing Joint or Married Filing Separate. If you lived apart the last six months of the year and have a qualifying child, you may qualify for Head of Household.

Head of Household

You may be able to file as head of household if you meet all the following requirements.

1. You are unmarried or considered unmarried on the last day of the year. 
2. You paid more than half the cost of keeping up a home for the year.
3. A qualifying person lived with you in the home for more than half the year (except for temporary absences, such as school). However, if the qualifying person is your dependent parent, he or she doesn't have to live with you.

See Table 4 to see who is a qualifying person. Any person not described in Table 4 isn't a qualifying person