The Treasury has questioned the merits of making KiwiSaver compulsory as a way of boosting national savings.
The idea is under consideration by the Savings Working Group, which was recently appointed by the Government to look at ways to lift national savings.
The Treasury says compulsory KiwiSaver payments would not be suitable for people who would be better off reducing their debt.
In a paper prepared for the working group, it identifies National Superannuation entitlements and interest-free student loans as significant obstacles to improving national savings.
The Government has already ruled out changes to those areas.