I have a divorce petition with the court already but still working through our agreement with a mediator. Does that qualify to file as Legally Separated?

[markanzalonesf]

Last year I filed Married filing separately.

[ThomasM125]

 No, the decree has to be final for you to file as single.

[guywong]

You are considered married by the IRS as long as your divorce is not final, or you are not "legally separated" from your spouse under a court order, by the last day of the year.  For more details, see Publication 504 (2022), Divorced or Separated Individuals

https://www.irs.gov/publications/p504

If you two are are amicable, filing a joint tax return is most often the best.  This is especially if you two have children together.  This is because only one spouse can claim a dependent on his/her tax return.  This is also true if one of you make much more money than the other.  The higher earner will pay a lot more tax even if you live in a community property tax as income earned after date of separation is no long community property.  

[ShirlynW · Accepted solution]

No, you are not legally separated.  Since you did not have a final divorce decree, you would had to have a separate maintenance by the last day of 2022.