On December 4, 2015, Mazdzer won the 2015–16 Luge World Cup Men's singles event at Lake Placid in the first-ever one-two finish for the United States in a men's singles luge World Cup event, with the 2014–15 winner and track record holder, Tucker West, coming in second.

[3] Until his 2015 win, Mazdzer's best finish at the FIL World Luge Championships was sixth in the singles at Whistler, British Columbia, in 2013.

[4] On February 11, 2018, Mazdzer won a silver medal in men's singles at the 2018 Winter Olympics in Pyeongchang.

[6] Mazdzer announced his retirement from luge in December 2023, stating that he wanted to spend more time with his family.

[12] Mazdzer met his Romanian-born wife, Mara, in the summer of 2017 and they became engaged in October 2019; they were married in Salt Lake City, Utah, on May 19, 2020.