In March, they won the gold medal at the 2013 World Junior Championships, the first American pair to win the title since 2007.

[12] Denney put no weight on her right leg for six weeks and then began physical therapy before returning to the ice in October 2015.

[13] During this time, Frazier worked on his skating skills under Marina Zueva and her team in Canton, Michigan.

Initially limited to basic stroking and crossovers, Denney began cautiously practicing jumps in late November.

By April 2016, they were training with Rockne Brubaker and Stefania Berton at the Fox Valley Ice Center in Geneva, Illinois.

In spring 2018, the pair decided to rejoin the coaching team of John Zimmerman and Silvia Fontana, who were based in Wesley Chapel, Florida.

[18] Denney/Frazier won the bronze medal at their Challenger event to start the season, the 2018 CS Autumn Classic International.

[18] At the 2019 U.S. Championships, Denney/Frazier won the silver medal, placing third in the short program and second in the free skate, making some errors on their jumps in the latter.

After placing sixth at the 2019 CS Nebelhorn Trophy, they won the bronze medal at 2019 Skate America, defeating reigning US national champions Cain-Gribble/LeDuc.

[22] She landed a clean triple Salchow in the free skate, though they botched their intended three-jump combination, and they placed second in that segment to finish third overall.

[23] Denney/Frazier struggled at the 2020 U.S. Championships, beginning in the short program where Denney fell on their throw and then popped their planned triple jump, resulting in them finishing sixth in that segment.

They began training in Irvine, California, at Great Park Ice, with coaches Todd Sand, Jenni Meno, Rafael Arutunian, Chris Knierim, and Christine Binder.

This event was attended by skaters training in the United States due to travel restrictions caused by the COVID-19 pandemic.

[35] Knierim/Frazier skated strongly at the Cranberry Cup International, where they won the silver medal behind Russian pair Evgenia Tarasova and Vladimir Morozov.

In September, they won the gold medal at the John Nicks Pairs Challenge, an ISU international competition in New York City.

[37] In their first Grand Prix event of the season, 2021 Skate America, Knierim/Frazier placed fourth and narrowly missed the podium, just 2.56 points behind reigning World bronze medalists Boikova/Kozlovskii.

[38] At their second Grand Prix event, the 2021 Internationaux de France, the pair won the bronze medal.

After arriving at the competition, Frazier began to feel unwell, and he tested positive for COVID-19 on January 5, the day before the short program.

[41] The pair was forced to withdraw from the competition, and Frazier shared an emotional video message in which he expressed his devastation over not being able to compete.

They placed a strong third in the short program segment with a clean skate and earned a new personal best score of 75.00 points.

As those countries' athletes comprised the entirety of the top five pairs at the Olympics, this had a big impact on the field for Worlds, and Knierim/Frazier entered the event as medal favorites.

Frazier, speaking after the free skate, noted that it was their first event of the season and that "tonight was a fight, so a lot of grit out there.

[54] Knierim/Frazier won the gold medal at their second Grand Prix event, 2022 MK John Wilson Trophy, by a dominant 21.66-point margin.

They earned all-new season's best scores and won both segments of the competition with a strong short program and some errors in the free skate.

In the short program, they skated cleanly except for a hand down by Frazier on their side-by-side jump, and earned a new personal best score of 77.65 to place second, only 0.43 points behind Miura/Kihara.

[60] At the 2023 U.S. Championships, Knierim/Frazier won their second national title by a dominant 31.11 points, the largest margin of victory in history, which surpassed their own previous record set in 2021.

[64] Knierim/Frazier declined assignment to the 2023 Four Continents Championships, opting instead to participate in Art on Ice shows in Switzerland.

[65] The leadup to the 2023 World Championships was a difficult time for the team, after their coach Todd Sand had a heart attack on March 2 and was hospitalized for an extended period.

They placed second in the short program after Frazier fell on his triple toe loop, but had an otherwise strong skate.

Knierim/Frazier became the first U.S. pair to medal in consecutive World Championships since their coaches Jenni Meno and Todd Sand did so in 1995 and 1996.