Kammala jumla mai zuwa: A ranar 18 ga Yuni, 2015 aka sanar da Brunson a matsayin memba na mutum 12 na 2015 USA Basketball Men's U19 World Cup Team don
2015 FIBA Under-19 gasar cin kofin duniya. Brunson ya sami MVP na gasar, bayan ya jagoranci ƙungiyar tare da taimakawa 5.6 da sata 2.1 don gasar. Ya buga wasan da ya kai maki 30 a wasan kusa da na kusa da na karshe da Girka, kuma ya zira kwallaye 14 da suka hada da 6 a cikin karin lokaci da kuma taimakawa 7, 5 da kuma sata a wasan zinare da Croatia. Brunson ya yi daidai da abokin aikinsa Harry Giles, tare da matsakaicin 14.0 don gasar. Ya mamaye wasannin biyu na karshe. Dangane da wannan wasan kwaikwayon, an amince da shi a matsayin dan wasan kwallon kwando na Amurka na shekara, a ranar 21 ga Disamba, 2015.