Justice Melissa Hart will step down from the Colorado Supreme Court effective Jan. 5, the Judicial Department announced unexpectedly on Friday.

Hart has been on an unexplained and unusual leave of absence from the court since Oct. 28. She told Colorado Politics in November that the leave was for “family and personal health reasons,” but provided no further details.

In her Dec. 19 letter to Chief Justice Monica M. Márquez, Hart acknowledged she has been battling “continuing health concerns arising from the two concussions I suffered in the spring of 2025,” and helping with other health challenges with her family.

“I remain deeply committed to the work that is central to Colorado’s Judicial Branch – preserving the rule of law and serving the public,” Hart wrote. “As you know, I am especially concerned about access to civil justice for low and middle-income Coloradans and making the family law system work for unrepresented litigants. … I joined the bench because I felt called to address these issues, and I plan to continue this work after retirement.”

She added that she hopes to “be a change-maker and a partner” with the judicial branch.

Hart, 56, is a 2017 appointee of then-Gov. John Hickenlooper. Her departure creates the first vacancy on the court in five years. The Supreme Court’s membership has been stable since Justice Maria E. Berkenkotter joined in 2021, after a long period of retirement-related turnover.

The upcoming appointment to the Supreme Court will be Gov. Jared Polis’ second in his two terms in office.

This breaking story will be updated.