Matthews said while the highest inflation rate since 1990 was a contributing factor, the war in Ukraine and increasing energy costs were adding to the problem.
Grey Power Federation president Jan Pentecost said the gulf between superannuation and household expenses continued to exceed the rate of inflation.
"As things are now, a single-person household with a no-frills lifestyle is having to draw down $10,000 a year from savings to manage in a provincial location, while a single person in a larger city needs an extra $16,500 annually, provided they have those savings," she said.
"Many do not."
Pentecost said some Grey Power members were not coping financially with their retirement, particularly those who lived alone or were renting, or living in pensioner villages or social housing.
"More than 40 per cent of our members are worried about their likely financial situation in 10 years from now."
"It is abundantly clear that national superannuation must be inflation adjusted each year and that supplementary allowances, particularly for accommodation, healthcare and energy costs, must be increased."
"We need a level playing field for eligibility to accommodation supplements as a matter of urgency."
Dr Matthews said it was important for New Zealanders to start planning and taking action now if they want to achieve a particular style of retirement, but low-income earners had limited ability to save.
"After decades of low-wage economy we have far too many people who will never own their own homes and who are forced to pay excessive rents that often exceed 40 per cent of their NZ Super ..."
"National superannuation is not adequate on its own for these people and many face a bleak future in retirement unless there is genuine intention by the Government to avoid a social calamity."
