[2][3] He also recorded 18 goals and 20 assists in 27 games for the NTDP in the United States Hockey League (USHL).
He primarily played on the top line with future Boston College teammate James Hagens.
[6] Stiga represented the United States at the 2024 IIHF World U18 Championships where he served as alternate captain and recorded six goals and five assists in seven games and won a silver medal.
[7][8] On April 30, 2024, in the final preliminary round game against Finland he recorded a hat-trick.
He scored the game-winning overtime goal against Finland in the gold medal game.