@Leo N very few people are "legally" separated. It would be quite unusual.
While you may have a separation agreement with your spouse that is legally binding, only if the Judge signs off on it would you be "legally" separated. That doesn't normally occur. Unless that step occurs, you are still legally married in the eyes of the IRS and filing SINGLE is not an option.
The IRS does make a huge distinction between "legally separated and divorced".
if you are LEGALLY separated or divorced, then you file SINGLE . If you are simply SEPARATED, then you file either MFJ or MFS.
There are options to file HOH when there are children involved, but since you have not indicated that is the case, let's leave that aspect lie.
Let's look at it this way. As of 12/31/24, could you legally re-marry? Ask your attorney😉.
