I am single and had a baby in October 2012. I understand I can claim my newborn as a dependent but can I claim head of household since the baby was not 6 months old as of 12/31/12?

Yes. If the baby was born or died during the year, then it only matters that he/she was with you for most of the time when he/she was alive during the year.

See 1040 (2012) (http://www.irs.gov/instructions/i1040/ar01.html#d0e2040)


If the person for whom you kept up a home was born or died in 2012, you can still file as head of household as long as the home was that person's main home for more than half of the part of the year he or she was alive.

Agreed; claim Head of Household.