From late 2010 to late 2011, he was based at the World Health Organization in Geneva to work on non-communicable disease prevention and control with a global focus.[8] From 2012 to 2015, he held leading positions across district health boards with Capital & Coast District, Hutt Valley, and Wairarapa. From 2015 to 2018, Bloomfield was chief executive at Hutt Valley District Health Board.[11] In the first half of 2018, Bloomfield was seconded to the Capital & Coast District Health Board where he was interim chief executive. Since June 2018, he has been the chief executive of the country's Ministry of Health and the country's Director-General of Health.[3][8] Since he started as the ministry's CE, he has taken leadership training at Saïd Business School at the University of Oxford.[6]