Most are currently contributing at either 3 or 4 per cent with those who are employed getting a further minimum 3 per cent employer contribution.
Neilson said its research had found most people wanted to save and save more but they either could not afford to do so or had not got around toit.
His proposal is expected to include lifting KiwiSaver contributions, while reducing taxes on the savings scheme to make it comparable to other investments.
Neilson also wants to encourage more savers to move from conservative funds, where most of the money is invested in cash and fixed-income investments, into more growth-oriented assets.
Changing the setting on the default KiwiSaver funds to a lifestages model where the level of growth assets is linked to age is under review by the Government. But there may be no change if the Government takes the same tack as the Retirement Commissioner's review.
It states that the default funds were set up with capital preservation in mind and it should be up to individuals to decide to move their money into a higher-growth investment fund or lifestages fund.
The review also made it clear that making KiwiSaver compulsory was not a good option as it would be perceived as an additional tax and would undermine the objective of encouraging individual responsibility and choice.
Martin Lewington, chief executive of Mercer, a KiwiSaver provider, said it was no surprise that the review came out against compulsion.
"I think we have been down that path before and found New Zealanders don't really like being told what to do."
But he was supportive of its widespread auto-enrolment recommendation.
The Government had planned to introduce auto-enrolment to all employed New Zealanders but delayed it in the last Budget because of cost concerns.
Bruce Kerr, executive director of Workplace Savings, said he would like to see auto-enrolment introduced as soon as the Government could afford it.