on february 18, 2016, mack was traded to the utah jazz in a three-team trade involving the hawks and the chicago bulls. the move reunited him with former butler teammate gordon hayward and former hawks assistant quin snyder. he made his debut for the jazz on february 21, recording a season-high 16 points and six assists off the bench in a 115–111 loss to the portland trail blazers. in the jazz's next game two days later, mack was elevated to the starting point guard role, replacing raul neto. he subsequently topped his season-high with 17 points in 32 minutes of action, as the jazz defeated the houston rockets 117–114 in overtime. on march 11, he scored a career-high 27 points in a 114–93 win over the washington wizards.