Joining the Flyers' American Hockey League (AHL) affiliate, the Philadelphia Phantoms, immediately after his junior career, he helped the team win the Calder Cup in 2005.

During his under-20 career, he tied as Canada's all-time leading scorer at the World Juniors and was named to back-to-back Tournament All-Star Teams.

He was joined by fellow rookies Mike Richards and R. J. Umberger, who were both also instrumental in the Phantoms' Calder Cup championship of the previous season.

After 37- and 53-point efforts in his second and third NHL seasons, respectively, Carter and the Flyers agreed to a three-year, $15-million contract extension on June 27, 2008, days before he was set to become a restricted free agent.

Carter was later called off for a hooking penalty and the Penguins scored to tie the game and eventually win in overtime.

[5] On February 23, 2012, Carter was traded to the Los Angeles Kings in exchange for Jack Johnson and a conditional first-round pick, reuniting him with former Flyer and close friend Mike Richards.

[6] On June 11, 2012, Carter scored the second of three unanswered goals on a five-minute power play in Game 6 of the 2012 Stanley Cup Finals against the New Jersey Devils.

[8][9] Early in the 2014–15 season, Carter was named the NHL's First Star of the Week for October 20–26 after scoring two goals and four assists in just two games.

This helped the reigning Stanley Cup champion Kings maintain a perfect 6–0 record during their season-opening homestand.

[10] On February 15, 2015, Carter passed the 500 career NHL point mark with a three-assist performance against the Calgary Flames in a 5–3 victory for the Kings.

[citation needed] In the 2016–17 season, Carter was named to his second All-Star game appearance, along with teammate Drew Doughty.

The following year, Carter moved on to the Canadian national under-20 team, playing in back-to-back World Junior Championships.

Carter had been joined on the World Junior squads by two future Philadelphia Flyers teammates, Mike Richards and Braydon Coburn.

[21] Carter then played for Canada at the 2014 Winter Olympics, where he scored a natural hat-trick against Austria, and eventually took home gold after helping defeat Sweden in the final.

Carter owns a house in Sea Isle City, New Jersey, which he bought when he was a member of the Philadelphia Flyers.

[citation needed] Carter is good friends with Mike Richards, his teammate from his tenure with the Flyers and the Kings.