[2] Because Wagner's father was in the army, she was a military brat when her family moved nine times during her childhood;[3] they settled in northern Virginia when she was ten years old.

[11][12] In July 2019, Wagner came forward and revealed that she was sexually assaulted as a 17-year-old by John Coughlin, a fellow figure skater who committed suicide the previous January after he was accused of multiple sex crimes.

In 1998, Wagner watched Tara Lipinski win the gold medal at the 1998 Winter Olympics in Nagano, Japan on television.

[6][9] Wagner later trained in Kansas City and Tacoma, Washington until her family moved to Portland, Oregon, where she was taught by Tonya Harding's former coach, Dody Teachman.

[23][24] At the 2006 U.S. Nationals in St. Louis, Missouri, Wagner finished fourth on the junior level, earning the pewter medal.

At the 2007 U.S. Nationals in Spokane, Washington, Wagner placed third behind Mirai Nagasu and Caroline Zhang, earning herself a spot on the World Junior Championships team.

She finished with the bronze medal behind Zhang and Nagasu, completing the first-ever American sweep of the World Junior podium.

Two weeks later, Wagner won her first senior international medal at the 2007 Trophée Éric Bompard in Paris, France.

At the 2008 Four Continents in Goyang, South Korea, Wagner finished twelfth in the short program, fifth in the free skate, and eighth overall.

[31] In June 2008, Wagner announced that she would be leaving her longtime coach Shirley Hughes to begin working with Priscilla Hill in Wilmington, Delaware.

[17] For the 2008–09 Grand Prix of figure skating season, Wagner was assigned to compete at 2008 Cup of China where she finished fourth.

For the 2009–10 Grand Prix season, Wagner was assigned to compete at the 2009 Rostelecom Cup, at that event she won the silver medal.

She also began to suffer violent full-body muscle spasms which her coach Priscilla Hill said were "some of the most horrific things I've ever seen.

[18][34] She quit her part-time job at American Eagle and used some of the money she had been saving for college in order to move across the country.

She placed first in a free skate which included six triples and won the gold medal ahead of two time world champion Mao Asada.

At her first Grand Prix assignment of the season, the 2012 Skate America, Wagner placed first in both programs and won her first gold on the GP series.

[38] At the 2012 Trophée Éric Bompard, she was second in the short and first in the long and won her second GP title,[39] qualifying for the 2012 Grand Prix Final.

At the 2013 U.S. Championships, Wagner placed first in the short program, second in the free skate after falling twice and two-footing her salchow jump, and was able to edge out Gracie Gold to win her second straight national title.

[42] Wagner's luggage that contained her skates was lost on her way to the 2013 World Championships but arrived before the evening practice on March 12.

[45] On April 24, John Nicks said he would no longer travel but would still coach Wagner at the Aliso Viejo Ice Palace.

[48] In the 2013–14 ISU Grand Prix season, Wagner won the silver medal at her first event, the 2013 Skate America.

Her next assignment was the 2013 Trophée Éric Bompard where she won gold and qualified for the 2013–14 Grand Prix Final in Fukuoka, Japan.

[49] She was named to the U.S. team for the 2014 Winter Olympics in Sochi, Russia, despite finishing behind third place Mirai Nagasu, due to her strong international record, which is considered under the selection criteria.

In August 2016, Wagner spent three days working with Charyl Brusch on her spins, saying, "She just kind of stripped everything down and had me go back to basics.

While she subsequently did not qualify for the 2016-2017 Grand Prix Final, Wagner quickly rebounded with her first silver medal at the 2017 U.S. Championships behind Karen Chen.

She was selected to compete at the 2018 Four Continents Figure Skating Championships, but opted to withdraw, giving her spot to alternate Angela Wang.

[66] Wagner was eventually invited to compete at the 2018 World Figure Skating Championships due to Karen Chen's withdrawal, but declined.

[13][70] Wagner was the color commentator for the 2020 European Figure Skating Championships in Graz, Austria broadcast on NBC on February 1, 2020, which was previously recorded on January 25, 2020; the play-by-play announcer was Chris Vosters.

She executed multiple triple-triple jump combinations in international competition including the 3Lz-3T, 3F-3T and 3Lo-1/2-3S, and successfully landed the 3Lz-3Lo at the 2008 U.S. Nationals.

Her signature elements included a Charlotte spiral and a bent-leg layover camel spin with both arms outstretched above her head.