Anderson finished the 1998-99 season with the Guelph Storm of the OHL, where he served as a backup to Chris Madden. In 21 games with the Storm, Anderson went 12-5-1 with a 3.10 GAA, helping the Storm reach the playoffs. In three playoff games for Guelph, Anderson went 0-2 with a 4.74 GAA. After the season, Anderson was drafted by the Calgary Flames in the third round, 77th overall, in the 1999 NHL Entry Draft.
He returned to the Storm for the 1999-2000 season, where he split the goaltending duties with Madden once again. In 38 games, Anderson had a 12-17-5 record with a 3.59 GAA. The Storm reached the playoffs, and in three games, Anderson went 0-1 with a 2.73 GAA and a .931 save percentage.
In 2000-01, Anderson became the starter for the Storm, as he appeared in 59 games, earning a record of 30-19-9 with a 2.63 GAA along with a .918 save percentage to win the OHL Goaltender of the Year award. In the playoffs, Anderson and the Storm struggled, as he went 0-4 with 4.25 GAA as Guelph was swept in the first round. Anderson then re-entered the NHL Entry Draft for 2001, as he failed to sign a contract with the Calgary Flames, who drafted him in 1999. The Chicago Blackhawks drafted Anderson in the third round, 73rd overall.
The Chicago Blackhawks assigned Anderson to the Norfolk Admirals of the AHL for the 2001-02, where he served as a backup to Michael Leighton. In 28 games with the Admirals, Anderson went 9-13-4 with a 2.86 GAA. He then played in a playoff game for the team, going 0-1 with a 2.86 GAA and .938 save percentage in 21 minutes of work.
Anderson spent the majority of the 2002-03 season with the Admirals, going 15-11-4 with a 1.94 GAA in 32 games with Norfolk. In the playoffs, he went 2-3 with a 2.61 GAA in five games. Anderson also made his NHL debut in 2002-03 with the Chicago Blackhawks. In his first NHL game on November 30, 2002, Anderson stopped all four shots he faced after replacing Jocelyn Thibault in the second period in a 4-1 loss to the Los Angeles Kings. Anderson then started his first NHL game the next night, on December 1, 2002 against the Mighty Ducks of Anaheim, where he made 23 saves in a 3-2 loss. Anderson finished the year 0-3-2 with the Blackhawks with a 4.00 GAA in six games with Chicago.
Anderson again split the 2003-04 season between the Admirals and Blackhawks. In 37 games with Norfolk, Anderson had a 17-20-0 record with a 2.11 GAA, followed by a 2-3 record and a 1.83 GAA in the playoffs. With the Blackhawks in 2003-04, Anderson went 6-14-0 with a 2.84 GAA in 21 games. After losing his first eight decisions with the team, Anderson won his first NHL game, and earned his first NHL shutout, as he made 30 saves in a 7-0 Blackhawks victory over the Columbus Blue Jackets on January 22, 2004.
With the 2004-05 NHL lockout cancelling the season, Anderson spent the entire season with Norfolk, however, injuries limited Anderson to only 15 games, where he had a 9-4-1 record and a 1.83 GAA for the Admirals. In six playoff games, Anderson was 2-4 with a 2.36 GAA.
Anderson spent the entire 2005-06 in the NHL, however, he found himself claimed on the waiver wire three times. On January 19, 2006, the Boston Bruins claimed Anderson from the Blackhawks, then on January 31, 2006, the St. Louis Blues claimed Anderson from the Bruins. Four days later, on February 3, 2006, the Blackhawks claimed Anderson from the Blues. Despite all the movement, Anderson did not appear in any games with the Bruins or Blues. In 29 games with the Blackhawks as the primary backup to Nikolai Khabibulin, Anderson went 6-12-4 with a 3.32 GAA. On June 24, 2006, the Blackhawks traded Anderson to the Florida Panthers for the Panthers sixth round draft pick in the 2008 NHL Entry Draft.
Anderson spent most of the 2006-07 season with the Florida Panthers AHL affiliate, the Rochester Americans. In 34 games with Rochester, Anderson went 23-10-1 with a 2.56 GAA, then went 2-4 with a 2.87 GAA in six playoff games. Anderson also appeared in five NHL games with the Panthers in 2006-07, going 1-1-1 with a 2.21 GAA. He earned his first win as a Panther on March 28, 2007, as he made 33 saves in a 3-2 shootout victory over the Atlanta Thrashers.
In 2007-08, Anderson stayed with the Panthers for the entire season, as he was the backup goaltender to Tomas Vokoun. In 17 games, Anderson went 8-6-1 with a 2.25 GAA and a very impressive .935 save percentage. Anderson set an NHL record for the most saves in a shutout, as he stopped all 53 shots he faced in a 1-0 win over the New York Islanders on March 2, 2008. Anderson then had 40 saves in his next game, also a shutout victory, as Florida defeated the Boston Bruins 1-0 in overtime on March 4, 2008. That also set an NHL record for most saves in consecutive shutouts, with 93. However, Anderson’s record of 53 saves in a single shutout was broken when Mike Smith of the Phoenix Coyotes made a 54-save shutout against the Columbus Blue Jackets on April 4, 2012.
Anderson was the backup once again to Vokoun in 2008-09, however, he appeared in 31 games due to an injury Vokoun suffered during the season. Anderson went 15-7-5 with a 2.71 GAA, as Florida narrowly missed the playoffs. After the season, Anderson became a free agent, and on July 1, 2009, he signed a two-year contract with the Colorado Avalanche.
Anderson joined the Colorado Avalanche for the 2009-10 season, and won the starting job from Peter Budaj in training camp. In his first season with the Avalanche, Anderson went 38-25-7 with a 2.64 GAA, .917 save percentage, and seven shutouts, helping the team make a surprising run into the playoffs. He won his first game with the Avalanche in his first start, a 5-2 Avalanche victory over the San Jose Sharks on October 1, 2009. In his next start, Anderson recorded his first shutout with the team, stopping all 35 shots in a 3-0 win over the Vancouver Canucks on October 3, 2009. Anderson became the fourth goaltender in team history to win 30 or more games, joining Patrick Roy, David Aebischer and Peter Budaj. He set the team record for consecutive starts to begin the season, as he started the first 15 games. He led the NHL in saves with 2047, and shots against with 2233.
Anderson made his NHL playoff debut on April 14, 2010, as he made 25 saves in a 2-1 victory over the San Jose Sharks. Four nights later, Anderson recorded his first ever post-season shutout, as he stopped all 51 shots fired at him, as Colorado won the game 1-0 in overtime. The Sharks would eventually defeat the Avalanche in six games, as Anderson had a 2-4 with a 2.62 GAA and a .933 save percentage.
He struggled to begin the 2010-11 season with the Avalanche, and eventually lost his starting job to Peter Budaj. With Colorado quickly falling out of the playoff race, and Anderson struggling with a 13-15-3 record and a 3.28 GAA, the club traded him to the Ottawa Senators for Brian Elliott on February 18, 2011.
Anderson finished the 2010–11 season with the Ottawa Senators, as he went 11–5–1 in 18 games, earning a 2.05 GAA and a .939 save percentage. In his first game as a Senator, Anderson posted a 47-save performance to shut out the Toronto Maple Leafs on February 19, 2011. On March 21, 2011, Anderson signed a four-year contract extension with the club.
During the 2011–12 season, Anderson was among the league leaders for wins with 29 in 56 games before being sidelined in Mid-February by a right hand injury sustained in a cooking accident. The injury prompted the Senators to acquire minor league goalie Ben Bishop from the St. Louis Blues near the trade deadline. Later in the season, Anderson’s Senators faced the Eastern Conference‘s top seeded New York Rangers and took the series to 7 games before losing 2–1 in the final game.
The lockout shortened 2012–13 season started off very well for Anderson. In his first ten games of the season he posted a record of 6–2–2 with a 1.49 GAA and .950 save percentage, earning consideration as an early Vezina Trophy favorite. He was named the NHL’s first star for the month of January (2013). However, Anderson suffered a sprained right ankle in a game against the New York Rangers on February 21, 2013, when he was knocked down by Rangers’ forward Chris Kreider.
Anderson played for the United States at the 2006 IIHF World Championship held in Riga, Latvia. In five games, Anderson went 3–2–0 with a 2.36 GAA, however, the USA finished in seventh place. Anderson once again represented the USA at the 2008 IIHF World Championship held in Quebec City, Quebec and Halifax, Nova Scotia, where he went 0-0-0 with a 5.63 GAA in two appearances as the USA finished in sixth place.
Anderson has instructed many goalie camps since being drafted in 2001. He currently instructs at Craig Anderson’s Goalie School in Chicago during summers.