I would think so also but turbo tax does not seem to allow you to put in nra and hr block asks you specifically if spouse in a nonresident alien when you answer the question about the spouse not having a ss number or tax id number. If you answer yes to nonresident alien it says you cannot efile although when you print out the tax return to mail, it puts nra in the appropriate box. I asked him if he could just override the question and manually put in the nra in-the form and he said it would not allow him.
If someone used a specific software that does allow it, I would appreciate knowing which one you used. The irs site for just receiving a stimulus check for people who do not need to file will also not allow married filing separately and was very clear if he is married you cannot put in single.