if.... under a divorce or separate maintenance decree and you don't qualify for another status, your filing status is single.  they may qualify for a different filing status though. 

 

Wouldn't legal separation make you Single for tax filing?

No, it makes you mfs

 

TurboTax disagrees

Legally separated filing options:
If tax law considers you "unmarried" because you got a decree of separation maintenance prior to December 31, you can file with "single" or "head of household" status.

You need to check if this is actually a "legal separation".  From what I understand, those are extremely rare.

From what I understand, those are basically a divorce, but for some reason the taxpayer's don't want to use the term "divorce" (perhaps religious reasons).

If it actually is a legal separation, then it is treated just like a divorce.  So the taxpayer's would be Single (or Head of Household, if they qualify).  But again, actual legal separation is quite rare.

If they are not legally devorced  it would be more beneficial for them to smoke the peace pipe and file one last joint return.

Note - check with your state.  For example in Maryland we don't have a "legal separation".  See from mdcourts.gov: "There is no such thing as a “legal separation.” In Maryland if you and your spouse live apart with the intention of ending your marriage, and if you do not have sexual intercourse during that time, that constitutes separation".

Remember, just like custody rules in divorce or orphan's court - the IRS has their own (and usually different) rules.

I see them when they want to be able to stay on the others health insurance through their employer.