Maierhofer, who has been a member of the Guardia di Finanza sports promotion group ( Gruppi Sportivi Fiamme Gialle ) since November 2013 , made his international debut at an FIS race for juniors in March 2007 in Toblach . In the following years he regularly took part in youth competitions, with the Alpine Cup in particular serving as an important competition series for comparing performance. At the European Youth Olympic Winter Festival 2009 in Szczyrk , he started in ski jumping , but only finished in the lower ranks in both the individual and the team. Despite further mixed results in the junior division, he made his debut on January 9, 2010 in Otepää in the Continental Cup , but missed the points. At the Nordic Junior World Ski Championships 2010 in Hinterzarten , Maierhofer was only used in the sprint, which he finished in 40th place. At the subsequent Junior World Championships in Otepää, he improved slightly to 25th place in the sprint and 29th place in the Gundersen singles. In the 2011/12 season he showed himself in rising form and was able to celebrate his first Alpine Cup victories and record points in the Continental Cup . At the Nordic Junior World Ski Championships 2012 in Erzurum he reached eleventh place in the sprint and 17th place in the Gundersen singles. Together with Samuel Costa , Roberto Tomio and Mattia Runggaldier , he won the silver medal with the team. He finished the season by winning the overall Alpine Cup.
In the summer of 2012, Maierhofer competed in the Grand Prix for the first time. He finished his first competition in Oberwiesenthal in twelfth place in the team sprint together with Samuel Costa, whereby he also won ten points for the individual evaluation due to the points system at that time. On January 5, 2013, he was used in Schonach for the first time in the World Cup and finished ninth with the team. In the individual, he only made his debut a week later in Chaux-Neuve , but ended up being beaten in 44th place. In the following weeks he faced the competition again in the Continental Cup , which he finished in 33rd place overall.
In the following years Maierhofer took part regularly in competitions of the Continental Cup, but remained largely unsuccessful. In addition, he started sporadically in the World Cup, but remained pointless in the individual. In December 2014, he tried his hand at the 10 km freestyle cross-country Alpine Cup in Hochfilzen , but was only able to achieve 109th place. At national level, Maierhofer was Italian runner-up in 2018. In the 2019/20 season he also competed regularly in the Continental Cup , where he regularly reached the points. At the home World Cup in Val di Fiemme , he had to settle for 40th place. A few weeks later, he achieved his best Continental Cup result to date with sixth place in Rena .