I was referring to the exception mentioned in the footnote of the SSA notice. Technically, if one "lived apart from their spouse for the entire year," they can be treated as single. Ask any agent what that means in practice. When I asked, the agent responded,"Did you sleep with your wife even once during the year." You can put any interpretation you want on that, but most people would consider that information none of the government's business.Cha! I'm still in the $144.60 category. I should spend more time on my investment income and less time on this site! Maybe there are others here who agree with that.
One more thing. The married and filing separately has nothing to do with sex, it has to do with relative income size. In case one spouse makes several times what the other one does.