More than 500,000 New Zealanders will be able to join KiwiSaver due to law changes from Monday.
About 2.9 million people already belong to the retirement savings scheme, but until now, over-65-year-olds had been locked out of joining.
It is one of a handful of law changes which take effect on July 1.
There are 747,900 people aged 65 and over in New Zealand, according to Statistics New Zealand and research by the Commission for Financial Capability shows nearly one in three (29 per cent) of over-65-year-olds are already in KiwiSaver.
• Canny View: Key changes to KiwiSaver