In November 2023, he was designated by Chief Justice John Roberts to serve as a judge of the United States Foreign Intelligence Surveillance Court of Review.

President George W. Bush initially nominated Tymkovich to the seat on the Tenth Circuit on May 25, 2001, and renominated him on January 7, 2003.

President Bill Clinton had nominated Christine Arguello to the seat, but she never received a hearing or a vote from the United States Senate.

[2][3] In September 2016, Tymkovich and his circuit colleague Neil Gorsuch were named as possible U.S. Supreme Court nominees by Republican presidential candidate Donald Trump.

[4] In 2018, Tymkovich was tasked with reviewing more than a dozen ethics complaints filed against U.S. Supreme Court Justice Brett Kavanaugh.

[5] On November 1, 2023, he was designated by Chief Justice John Roberts to serve as a judge of the United States Foreign Intelligence Surveillance Court of Review.

But the Tenth Circuit affirmed the conviction after noting the statement in Heller that "nothing in our opinion should be taken to cast doubt on longstanding prohibitions on the possession of firearms by felons.

In an opinion written by Judge Tymkovich, the Tenth Circuit held that the Eleventh Amendment protected States from lawsuits based on professional licensing decisions.

In an opinion written by Judge Tymkovich, the Tenth Circuit held that the First Amendment does not protect knowingly false statements of fact.