The Government wants more of the baby boomer generation to keep working past the traditional retirement age to help grow the economy over the next 40 years.
A report by the Ministry of Social Development concludes that by 2051, those over the age of 65 could make up 10% of the workforce.
The report says that could mean an annual increase of $9 billion in earnings by 2051. There would also be an extra $1.6 billion in tax revenue and $35 billion more in consumer spending by 2051.
At the last Census there were 62,000 people aged over 65 who were working. By 2031, there are expected to be 240,000.
Senior Citizens Minister John Carter says there will be a serious skills shortage without the baby boomers and staying on in the workforce will ultimately create more jobs for younger people.