What time of marriage qualify for joint filing?

[yaorui89thu]

For example, if a couple get married at the beginning of 2019, can they file jointly for federal income tax of year 2018?

[DDollar · Accepted solution]

It doesn't matter.  If you were married on December 31, you are considered married for the entire year for tax purposes.  If you were married all year but you divorced and it was finalized on December 31, then you were unmarried all year for tax purposes.  You cannot consider yourself married for 2018 if you didn't get married until 2019.

[VolvoGirl]

So it goes by your status on December 31, each year.