The significant economic costs of health inequities between Māori and non-Māori adults in New Zealand has been highlighted in an Indigenous-led study. The study used quantitative epidemiological methods and cost-of-illness methodology within a Kaupapa Māori theoretical framework. Deidentified data from national collections held in government agencies was reviewed for the period 2003-2014, including all hospitalisations, mortality, outpatient and primary care consultations, laboratory and pharmaceutical usage and accident claims for individuals aged ≥15 years. Health inequities between Māori and non-Māori adults were estimated to cost NZ$863.3 million per year. Direct costs of NZ$39.9 million per year included ambulatory sensitive hospitalisations and outpatient care, as well as cost savings from underutilisation of primary care. Indirect costs of NZ$823.4 million per year were calculated from years of life lost and lost wages. The study authors noted that the ‘cost of doing nothing’ is predominantly borne by Indigenous communities and society.