The latest figures, released under the Official Information Act, showed 22 board chairs and four commissioners - installed at Southern DHB after the board was sacked - have spent $425,408 in the three years, for about 30 days of work each year.
The board members, 10 on each board except Southern, have collectively spent $564,764, taking the total to $990,172. Some DHBs did not provide all expenses.
The expenses include international and domestic flights, meals, accommodation, taxi fares, parking costs, mileage, conference registration, professional development, memberships including to Air New Zealand's Koru Club, phones and gifts.
The higher spenders were board members or chairs who travelled overseas including former Counties Manukau chair Dr Lee Mathias who attended a New Zealand Trade and Enterprise event between Turkey and New Zealand in May 2015.
The induction for new board members after the latest local government elections in late 2016 also cost thousands in domestic flights to Wellington.
Other high costs were incurred in domestic travel when board chairs or deputies lived outside the region or members had to fly to other cities in New Zealand for meetings.