[4] Mroz's mother was at one time a synchronized skater and his father an ice hockey player.
In addition to singles skating, he also trained as an ice dancer and tested in that discipline up to silver level in the U.S.
He won both the short program and the free skate at his regional competition to win the gold medal overall.
At Sectionals, Mroz placed fourth in the short program[15] and second in the free skate to win the silver medal overall.
[18] Following the event, Mroz competed at the 2004 Copenhagen Trophy, where he won the novice men's competition after winning both segments.
At his regional championships, he placed second in the short program[20] and in the free skate to win the silver medal overall.
Competing at the Southwestern Regional Championship, Mroz won the short program[25] and the free skate to win the gold medal overall.
[26] This win qualified him for the 2006 Midwestern Sectionals where Mroz competed for the first time under the ISU Judging System.
Competing on the junior level for the first time in his career, Mroz won both the short[33] and free programs to win the gold medal.
[43] At his second event in Chemnitz, Germany, he again placed 4th in the short program and won the free skate to win the gold medal overall.
[57] In the free skate, Mroz placed 9th [58] after landing a 4T, but making errors on several other jumps, including his 3A.
[60] In his debut at the senior World Championships, Mroz skated a strong short program to place 8th in that segment of the competition.
[62] His placement, combined with that of World Champion Evan Lysacek, earned the United States the maximum three entries to the 2010 Winter Olympics.
[63] Mroz won his first senior Grand Prix medal, silver, at the 2010 Cup of China.
[64] He landed a quad Lutz successfully on September 16, 2011, in the short program at the 2011 Colorado Springs Invitational.
[65][66][67] The International Skating Union subsequently ratified the jump as the first successful quad Lutz landed in a sanctioned competition.
Mroz became the first skater to land the quad Lutz in an international competition on November 12 in the short program at the NHK Trophy.
[68] After ending his competitive career, Mroz began skating in Willy Bietak's ice shows on Royal Caribbean cruise ships.