However, the option of a straight capital gains, at a set rate, is not included.
The group was established by the Government to look at whether there should be any changes to the tax system, including a potential capital gains tax - excluding the family home.
The head of the working group, Sir Michael Cullen, presented the interim report late this morning.
The group has received about 6700 submissions and spoke with business and community groups in roadshows across the country.
The group is proposing two options for taxing capital gain: any gain from the sale of assets taxed at roughly the marginal income tax rate, and the second a regime under which a portion of the value of certain assets would be subject to tax, for example rental properties, to be paid each year.
However, Sir Michael said neither of these options were actual recommendations.
The report found there was "significant scope" to use tax to "sustain and enhance" New Zealand's "natural capital", including options like a waste disposal levy, "strengthening" the Emissions Trading Scheme, and congestion charges.
It also proposed removing the tax on employer contributions to superannuation schemes for those earning less than $48,000 a year.
The working group made no final recommendations about income tax rates, but suggested a progressive approach would be to reduce rates for the lower threshold tax brackets.
Public feedback will now be sought before the working group releases its final report in February 2019.
