Married, filing separtely Spouse in Puerto Rico

I am currently separated from my spouse, that has lived in Puerto Rico for almost 2 years, I live in California. We are married, filing separately, but I am unable to enter his state of residence (as PR is not considered a state), on the form. Is there a way to file this way? He is a government employee, and had to file taxes, but didn't have to pay any in Puerto Rico. We are also looking at itemizing deductions (as he owns a house there, and I own one here in CA). Is this possible, if he doesn't pay taxes, and how do I enter his residence on the form?

posted