Just prior to the 2018-19 season, Frazier was claimed off waivers by the New Orleans Pelicans. He picked up a role with the team right away, and he ended up appearing in 47 games. Frazier also started 17 of those contests. He made 45.1 percent of his field goals with New Orleans, scoring 5.0 points per game. Frazier also averaged 4.4 assists and 2.9 boards for the Pellies. However, he was waived by the Pelicans in February. Roughly 18 days later, Frazier signed a deal with the Bucks for the remainder of the season. Despite playing for arguably the best team in the East, Frazier was still able to carve out a role in Milwaukee. He appeared in 12 games, starting two of them. His scoring average actually improved with the Bucks, as he averaged 6.3 points per contest. He also put up 3.5 assists and 2.6 rebounds a night with Milwaukee. Frazier ended the regular season with a bang. On Apr. 10, he played all 48 minutes against the Thunder, scoring 29 points and dishing 13 assists. Frazier appeared in 11 of the Bucks' 15 playoff games, providing just under four minutes a game of backcourt bench support.

Frazier appeared in 59 games for the Washington Wizards during the 2017-2018 campaign, starting 11 of those contests. Frazier averaged 3.0 points, 1.9 rebounds and 3.3 assists per tilt. Frazier scored in double figures twice during the regular season. He posted a season-high 11 points against Portland on Nov. 25. Frazier's best game of the season came on Jan. 27 at Atlanta. In a 129-104 victory, Frazier stuffed the stat sheet, dishing out a season-high 14 dimes while also tallying four points, three rebounds, two blocks and two steals. Frazier managed at least five assists in 16 games during the regular season. His best month was November. Frazier averaged 4.0 points, 2.6 rebounds and 3.4 assists per contest. Frazier also appeared in two playoff games for the Wizards, although he failed to score in both contests.

In his third NBA season, Frazier appeared in 65 games for the Pelicans. He made 35 starts and averaged 23.5 minutes per game, which he translated to averages of 7.1 points, 5.2 assists, 2.7 rebounds and 0.9 steals. In the season-opener against the Nuggets on Oct. 26, Frazier posted 15 points, 11 assists, five rebounds and four steals. Two nights later against the Warriors, Frazier had 21 points, 10 assists and six rebounds. On the season, the Penn State product scored in double-figures 21 times and handed out at least 10 assists eight times. Against the Suns on Dec. 11, Frazier recorded a career-high five steals. In that same game, he registered a 14-point, 11-rebound, 11-assist triple-double, becoming just the second Pelicans player in franchise history to have a triple-double off the bench. In a win over the Hawks on Nov. 22, Frazier matched his season-high with 21 points to go with 14 assists, five rebounds and three steals. He hit a season-high three of his four three-point attempts in that contest.

Frazier split his second NBA season between the Trail Blazers and the Pelicans, appearing in 51 total games and posting cumulative averages of 5.1 points, 3.2 assists and 2.2 rebounds. In 35 appearances for Portland, Frazier averaged 7.8 minutes per game, which he parlayed into averages of 1.5 points, 1.2 assists and 1.1 rebounds. On Feb. 18, Frazier was waived by the Trail Blazers. He subsequently signed a 10-day contract with the Pelicans on March 16. On March 26, he signed with New Orleans for the remainder of the season. On March 16 against the Kings, Frazier made his Pelicans debut, playing 27 minutes off the bench and finishing with 14 points and nine assists. He went on to score in double figures in 11 of his first 12 games with New Orleans, averaging 13.8 points, 6.3 assists, 4.2 rebounds and 1.4 steals in that span. Frazier notched double-digit assists in four of the final seven games of the regular season. In the season finale on April 13 in Minnesota, Frazier went for a career-high 15 assists.

Undrafted out of Penn State in 2014, Frazier initially signed a training camp deal with the Celtics but was waived prior to the start of the regular season. On Feb. 5, he signed a 10-day contract with the 76ers. Frazier went on to appear in six games for Philadelphia (three starts), averaging 5.7 points, 7.2 assists, 3.2 steals and 1.0 steal in 28.5 minutes. In his NBA debut on Feb. 6 in Boston, Frazier had five points, 11 assists, five rebounds and two steals in 35 minutes. On Feb. 24, he was released by Philadelphia. Frazier subsequently signed a multi-year deal with Portland on Mar. 30. He appeared in five games for the Trail Blazers, posting 4.6 points, 3.4 assists and 1.8 rebounds in 13.6 minutes per contest. In the regular season finale against Dallas on Apr. 15, Frazier went for 13 points, 10 assists and four rebounds. Frazier also spent significant time in the D-League as a rookie. He appeared in 41 games for the Maine Red Claws, posting averages of 16.1 points, 9.5 assists, 7.1 rebounds and 1.7 steals, with four triple-doubles and 11 double-doubles. Frazier was named both the 2015 D-League Most Valuable Player and Rookie of the Year, in addition to notching All-D-League First Team and All-Defensive Second Team honors.