[1] As a junior in 2002–03, he earned first-team all-state honors after averaging 14.5 points, 8.3 rebounds, 5.5 blocks and 2.7 assists per game.

[2][4] In his sophomore season, he was again disrupted, managing just 16 games after he was deemed ineligible to play during the second semester due to poor grades.

[2][4] In his senior season, led the team with 40 blocks, while recording four double-digit scoring performances, including a career-high 14 points in the NCAA tournament against Kansas State.

[6] In February 2009, he left Oyak and signed with the Seoul SK Knights of South Korea for the rest of the season.

[11] On August 21, 2011, Stiemsma signed with BC Sukhumi of the Georgian Superliga[12] but left before appearing in a game for them.

[14] On December 28, 2011, he made his NBA debut, recording 2 points, 6 blocks and 4 rebounds in a 78–97 loss to the New Orleans Hornets.

[16] On June 29, 2012, the Celtics extended a $1.05 million qualifying offer to Stiemsma, thereby making him a restricted free agent.

[18] Two days later, the Celtics withdrew their qualifying offer to Stiemsma, clearing the way for the Timberwolves to sign him as an unrestricted free agent.

[26][27] On September 12, 2016, Stiemsma signed with the Portland Trail Blazers,[28] but was waived on October 21 after appearing in four preseason games.

[29] On September 12, 2019, the Minnesota Timberwolves announced that they had named Stiemsma as player development associate.