KiwiSaver accounts he managed had reached $10,000 on average.
"We realise KiwiSaver is a good idea - we have joined it. Now is the time to know how to get the most out of your money."
Many people could not answer three basic questions. They were: who their fund manger was; how much money they had in their account; and in what fund their money was invested.
"If you can't answer those questions, your provider is not communicating well enough," Mr Foster said.
As many people were enrolled into a scheme run by a default provider, they appeared satisfied to let the funds "set and forget".
However, the "set" should not be joining the fund. Instead, it should be the decision on whether to have the money go to a conservative, balanced or growth fund.
"Hopefully, it is a case of as the account balances grow, people will take a more active view on how their money is invested."
To date, conservative options had performed better than the balanced and growth options, which had a higher weighting in sharemarket investments. The gap had been closing in the past three years, he said.
Recent figures showed there were more than two million KiwiSaver members with a combined total of $12 billion in investments.
New members were enrolling at more than 15,000 a month.
However, more than half of members were contributing only the minimum 2% of their salary or wages although the contribution was scheduled to go up to 3% in April next year.
Those people already contributing either 4% or 8% of their salary or wages would not be affected by the April changes, Mr Foster said.
More than 90% of employers were at present contributing only the legislated minimum of 2% into their employees' KiwiSaver accounts. Those employers would be required to increase their contribution to 3% in April.
Most KiwiSaver members aged 18 and older qualified for the annual government contribution which matched 50c for every $1 of member contributions made up to a set amount. But last year, only 45% of members qualified to receive the government contribution of $521.43 in full, he said.
"This may be due to the high proportion of Kiwis not contributing enough - the minimum 2%. Also, many self-employed and non-working members do not realise they are actually eligible to receive the government contribution. They can make their KiwiSaver contributions directly with their KiwiSaver provider."
The KiwiSaver first-home benefits had proven popular, with thousands of first-home buyers taking the opportunity to withdraw their KiwiSaver savings and also apply for the $3000 to $5000 Housing New Zealand subsidy, Mr Foster said.
