He is a Race Director for the International Motor Sports Association and also served as a Race Director for the IndyCar Road to Industry ladder series during their growth years from running USF2000 only to their additional ownership of Pro Mazda and Industry Lights. Hembrey has worked in the industry since 1979 and founded Comp8 Motorsports, a professional motorsport service enterprise in 2003. Hembrey was the first general manager of the revitalized Transport-Am Series when SCCA restarted the series in 2009.
The professional series raced at tracks beside other professional and amateur event.
Series Manager, International Motor Sports Association Single Make and Challenge Series (2015-present)
Race Director, IMSA GT3 Cup Challenge (2012–2015)
Race Director, Lamborghini Super Trofeo (2013–2015)
Race Director, IMSA GT3 Cup Challenge Canada (2013–2015)
Race Director, United States. F2000 National Championship (2013–2014)
Race Director, Pro Mazda Championship (2013–2014)
Director of Competition, Traxxas TORC Series (2012–2013)
Director of Competition, Transport-Am Series (2011–2012)
General Manager / Race Director, SCCA Transport-Am Series (2009–2011)
Director of Competition / Race Director, Formula Drift (2004–2010)
Race Control, Formula 1 United States Grand Prix (2000–2007), Canadian Grand Prix (1995–1999)
Assistant Chief Steward, Mazda MX-5 (2006–2009)
Race Operations, SPEED World Challenge (2000–2009).