I am filing married separately. he will itemize . he is head of household and will itemize. he owes back taxes, and tax lawyer advised filing seperatly

[Zbucklyo · Accepted solution]

If you are married, and lived together at any time during the last six months of 2016, your husband is not entitled to file as head of household. If he is entitled to file as head of household, and itemizes, and you file separately from him, you do not have to itemize your deductions.

[TomD8]

Some other considerations:

If he is ineligible for HOH as per Zbucklyo's explanation, and he files MFS and itemizes, then you must itemize too - even if the standard deduction would be more advantageous to you.  This is one of the disadvantages of MFS.  With MFS, if one spouse itemizes, the other must itemize too.

MFS is even more complicated if you live in a community property state.

It may be more advantageous to you to file MFJ with a Form 8379 Injured Spouse allocation.  This would preserve your portion of a joint refund while preserving the advantages of filing MFJ.