Hoffman began skiing at age four. His club is the Ski and Snowboard Club Vail. Hoffman's coaches are John Callahan, Zach Caldwell, Jason Cork, Matt Whitcomb, Chris Grover, Eric Pepper, and Dan Weiland.
Hoffman opened the 2012–13 season well, placing a career-best 19th in the second stage of the Nordic Opening at Ruka, a 10 km freestyle race; he went on to place 26th in the final standings of the Ruka Triple. He scored his first top 10 finish two weeks later at Canmore, placing 8th in the 30 km skiathlon. Hoffman also completed his first Tour de Ski, finishing 46th with a best stage finish of 17th in the final climb. He came in 8th in the 4x10k Relay in the 2012 World Cup in Nove Mesto, Czechoslovakia. He came in second in the 15k CL at the U23 2012 World Championships, the highest finish ever by an American at the U23 World Championships. Hoffman won the 2012 U.S. Championship Title in the 30k CL, in Rumford, Maine. At the 2013 World Championships in Val di Fiemme, Italy, Hoffman improved on his results from two years before. He finished strong to place 15th in the 15 km freestyle, his best World Championship result to date. In the 50 km classic mass start he placed 27th after going with an early five-man breakaway. He was the top American in both races. He placed 10th in the 4x10k Relay. Hoffman narrowly qualified for his first World Cup Final in Falun, Sweden, scoring seven World Cup points at the last opportunity to move to 47th in the World Cup overall standings as the top 50 qualified for the final weekend. He eventually finished 48th in the overall World Cup and 36th in the distance World Cup.
2013–14
Hoffman underwent shoulder surgery in the off-season, hoping to eliminate a recurring shoulder dislocation problem. He placed a career-best 9th in the season-opening Ruka Triple, being the fastest skier in the final stage and thus receiving the maximum 50 World Cup points for a stage win. Hoffman also had the fastest time on the day during the 35 km pursuit during the Tour de Ski. Hoffman represented the United States at the 2014 Winter Olympics in Sochi, Russia, and came in 11th in the Men's 4x10k Relay, 26th in the Men's 50k Freestyle Mass Start, 31st in the Men's 15K classic, and 35th in the Men's Skiathlon 30K in which he crashed as he rounded a 180-degree corner turn and broke his ski pole. In November 2014 Hoffman crashed and broke his left fibula above the ankle and suffered medial collateral ligament damage when his skis got caught in the course fencing at the Kuusamo World Cup in Finland. He had surgery to implant pins and a plate near his ankle to repair his leg. In the 2015 World Ski Championships in Falun, Sweden, he placed 11th in the 4x10k Relay.
2015-16
In 2015-16 Hoffman was the top distance racer in the United States, as he won several World Cup points throughout the season. His best result was 19th in a 10k freestyle race in Toblach, Italy. He also had his career-best Tour de Ski, in which he finished 22nd overall in the Tour standings.
Rukatunturi, Finland