When the Denver-based federal appeals court convenes next week to hear oral arguments, six new faces will be staring down from the bench.

No, the U.S. Court of Appeals for the 10th Circuit has not added six new members. It still consists of 12 presidentially nominated, U.S. Senate-confirmed judges and a handful of semi-retired senior judges. They hear appeals in three-member panels in cases arising from Colorado, Oklahoma, Utah, Kansas, New Mexico and Wyoming.

But for the first time in over 12 years, the 10th Circuit’s upcoming oral argument session will feature trial judges from various district courts sitting on the appellate panels.

In a practice known as “sitting by designation,” federal judges can temporarily hear cases in courts inside or outside of their geographic circuit, depending on the courts’ needs.

“For many years, it was common practice for the circuit to invite district judges to sit by designation in order to promote collegiality, provide insight into the appellate process, and assist with particularly heavy oral argument calendars,” said Chris Wolpert, the 10th Circuit’s clerk. “The court decided to invite district judges to sit by designation for our January 2026 term of court for the same reasons we previously extended such invitations.”

He clarified that, although the January session is “relatively busy,” the court “is not struggling to keep pace with its current workload.”

The six U.S. District Court judges who will be joining the arguments are:

• Chief Judge John F. Heil III of the Northern District of Oklahoma, a first-term appointee of President Donald Trump
• Senior Judge Kathryn H. Vratil of Kansas, a George H.W. Bush appointee
• Judge Robert J. Shelby of Utah, a Barack Obama appointee
• Judge Holly L. Teeter of Kansas, a Trump appointee
• Judge Matthew L. Garcia of New Mexico, a Joe Biden appointee
• Judge Ann Marie McIff Allen of Utah, a Biden appointee

“Sometime last fall, the Tenth Circuit solicited interest from district judges to sit by designation, and I put my name in the proverbial hat,” Garcia told Colorado Politics in an email. “I also hope it’s a positive and educational experience for my law clerks, who work extremely hard at their jobs. They are quite excited to participate in the appellate process firsthand.”

Teeter said she learned in the fall that she would be participating in the circuit’s arguments, and she has prepared in generally the same way as she does on her district court.

“She is happy to help with the caseload and is interested in experiencing a different role within the judiciary,” Teeter’s chambers wrote in an email.

Wolpert said the last time district judges sat by designation on the 10th Circuit was in September 2013. He did not know whether the court had ever had six district judges participate simultaneously in arguments, but he said all the judges who responded to the 10th Circuit’s invitation and had availability in January were scheduled for the sitting.

Already, the 10th Circuit has issued one decision in which Allen, from Utah, was one of the panel members. Wolpert said that the case was intended to have oral arguments next week, but the panel opted to resolve the appeal on the written materials alone last week.

Judge Timothy M. Tymkovich of Colorado, who has been a 10th Circuit judge since 2003, told Colorado Politics that when he first arrived, the court welcomed judges from elsewhere at almost every session of oral arguments. But the practice stopped when the caseload could be handled with circuit judges alone.

“The Ninth Circuit pretty much has a standing invitation because their caseload is so heavy,” he said, referring to the most populous circuit largely covering the Western states. Tymkovich said he has heard cases in the Ninth Circuit on four occasions.

Although a judicial committee oversees assignments of judges between circuits, Tymkvoich noted all of the active judges on the 10th Circuit can sit on the various district courts within the jurisdiction, as he has done on Colorado’s trial court.

When the U.S. Supreme Court in 2020 expanded federal criminal jurisdiction in Oklahoma based on historical tribal boundaries, Tymkovich, who was then the 10th Circuit’s chief judge, “asked every judge in the 10th Circuit if he or she were willing to go take a case down there,” he said.

“I think it’s valuable for appellate circuit judges to have some exposure to what the district courts do and what it’s like. Conversely, I think it’s valuable for district court judges to have the opportunity. When they sit on an appellate court, it’s a different experience, different skill set,” Tymkovich said. “Even when I go to a place like the Ninth Circuit, which is another circuit court, the way they do business has important differences from the way the 10th Circuit does. I think I’ve learned from being exposed to the way different courts work.”