The long-term cost of welfare beneficiaries is $78.1 billion over their potential working life.
An independent study commissioned by the Ministry of Social Development used data from the past 20 years.
It looked at invalid, sickness, unemployment and domestic purposes benefits as well as other assistance like accommodation supplements.
The report used a baseline of people receiving any of those benefits in the 2010-2011 year.
It applied economic forecasts and adjustments to show they will cost the state $78.1 billion, up to the age of 65.
The ministry intends to use the information to formulate policy.