Thorbjornsen captured the 2018 U.S. Junior Amateur Championship at Baltusrol in extra holes over Akshay Bhatia and then made the cut in the U.S. Open at Pebble Beach Golf Links the following year. He is the only Junior champion to play 72 holes under the new U.S. Open exemption that was started in 2018 by the USGA that grants the reigning Junior Am champ a spot in the field. Thorbjornsen qualified for his second U.S. Open on June 6 via an 8-for-3 playoff at Century and Old Oaks Country Clubs in Purchase, N.Y., after shooting 2-under 138 over 36 holes. He is a rising junior at Stanford University. He recently was named to the 2022 USA Palmer Cup Team. Thorbjornsen won the 2021 Western Amateur and Massachusetts Amateur, defeating 2017 U.S. Mid-Amateur champion Matt Parziale in the final match. He currently resides in Wellesley, Mass., not far from The Country Club. In 2020, he reached the quarterfinals of the U.S. Amateur at Bandon Dunes with fellow Cardinal Karl Vilips serving as his caddie.