Coach John Beilein announced McGary's decision Friday, saying the 6-foot-10 forward would enter the NBA draft.
McGary says in a statement issued by the school he made a "poor decision" and was notified of the marijuana test result after the Final Four. He says he regrets disappointing family, coaches and the administration, but all have been "understanding and helpful."
McGary turned down a chance to enter the draft last year as a likely first-round pick and ended up having back surgery last season, putting his standing as an NBA prospect in doubt.
Beilein says McGary "injected an enthusiasm that cannot be matched."
Full statement from McGary:
"My family and I want to thank everyone for giving us privacy and the time to make this decision. As you know, it was important for us to weigh all the factors that go into something like this. With that being said, I am ready to move on to the next stage in my life and enter the NBA Draft. Being a part of a program that values integrity, it is important to let everyone know of a poor decision I recently made. I tested positive for marijuana during the NCAA Tournament. We were notified of that result after the Final Four. I regret thoroughly disappointing my family, coaches and administration. Despite all of this they have been understanding and helpful over the last couple of weeks. I take full responsibility for this poor choice and want to apologize to everyone, especially those I have grown close to during my fabulous two years at the University of Michigan. I love the University of Michigan and all it has allowed me to do. I have had my ups and downs, especially with my injury this season. I want to thank all the fans for embracing me. This has been the best two years of my life and I have some unbelievable memories. I know that I will be a Wolverine forever. Go Blue."
Full statement from Beilein:
"Mitch has had a tremendous impact on our program from the moment he committed to us. He has injected an enthusiasm that cannot be matched. This is why he is loved by the coaching staff, his teammates and Wolverine fans. The progress he has made on and off the court has been outstanding. His willingness to face a personal issue head on and his positive work ethic during his recent injury have helped him to grow in many ways. We know that he will put all of his energy and effort toward achieving his goals. We will continue to assist and support Mitch as he pursues a career in the NBA."
McGary helped UMM go 59-17 overall and 27-9 in Big Ten Conference play over the past two seasons. He was instrumental in U-M's return to the Final Four in 2013, when the Wolverines advanced to the national title game against Louisville.
This past season, he helped Michigan win its first outright Big Ten regular-season title in 28 years, earn its first No. 1 seed at the Big Ten Tournament and advance to the title game for the first time since 1998, as well as a second straight trip to the NCAA's Elite Eight.
The 2014 NBA Draft is scheduled for June 26 at the Barclays Center in New York.
Mitch McGary | Michigan Career Facts
• 2014 Preseason All-American Associated Press, USA Today and Sporting News (first team); Blue Ribbon College Basketball and Athlon Sports (second team)
• 2014 Preseason All-Big Ten
• 2013 NCAA Final Four All-Tournament Team
• 2013 NCAA Tournament All-South Regional Team
• Two-time Big Ten Freshman of the Week
• Seven career double-doubles
Recent Michigan early entries to the NBA Draft
Manny Harris, Jr. (2010) -- Undrafted
Darius Morris, So. (2011) -- Los Angeles Lakers (2nd, 41st pick)
Trey Burke, So. (2013) -- Minnesota Timberwolves (1st, 9th pick), traded to Utah Jazz
Tim Hardaway Jr., Jr. (2013) -- New York Knicks (1st, 24th pick)
Glenn Robinson III, So. (2014)
Nik Stauskas, So. (2014)
Mitch McGary, So. (2014)