@ericgarcia828 , assuming that you are a US citizen/Resident ( Green Card ) ,  your spouse is NRA,  and you have your qualifying  , dependent child ( children ) for whom you main a home, to claim Head-of-Household you must satisfy  either  (a) unmarried  or (b) considered unmarried .   If your spouse  ( NRA ) lived with you  at least for the last six months of the year, then you cannot satisfy the  "considered unmarried " clause -- spouse being NRA does  not invalidate the marriage .

Does this answer your query   ( it is not you wanted to hear -- sorry ) ?

On the irs website it says:

If you are a U.S. citizen married to a nonresident alien, you may qualify to use the head of household tax rates. You are considered unmarried for head of household purposes if your spouse was a nonresident alien at any time during the year and you do not choose to treat your nonresident spouse as a resident alien. 

Where does it say I can't file as HoH?

@ericgarcia828 , you are CORRECT  and I am WRONG --- NRA is not a US person and as such you are considered unmarried  - this is true for federal purposes -- you have to view the state rules  for State purposes.

Sorry