Treasurer Scott Morrison says the government is open to the "full plethora" of options for tax reform including the GST and Medicare levy.
Mr Morrison met with state and territory treasurers in Sydney on Friday where he provided them with a detailed treasury-costed list of possible tax system changes.
He confirmed the list included the GST and Medicare levy.
Mr Morrison's asked the treasurers to provide their own proposed changes to state-imposed taxes for discussion at the next meeting.
"We're talking about the plethora of options that exist at the federal level," Mr Morrison told reporters after the meeting.
However, the treasurers were in a "discovery phase" and he would not be drawn on which options the federal government was leaning towards.
"I think Australians would expect us to work methodically through what all the options are, because at the end of the day this is about ensuring Australians have a strong economy ... that's producing jobs and producing the revenue that is necessary to deliver important services."
The treasurers also discussed productivity including greater competition - based on advice from the recent Harper review - and more spending on infrastructure.
"The productivity challenges that we have are now without doubt the most important thing we must collectively address," Mr Morrison said.
The last major competition policy review had led to a 2.5 per cent boost in economic growth, he said.
Also on the agenda was how to better use the $11 billion spent on public housing and accommodation support each year.
Opposition Leader Bill Shorten told reporters in Sydney he didn't accept the GST base needed to be broadened or its rate raised.
"The Labor party doesn't support an increase in the price of everything," he said.
Instead the government should seek to ensure multinationals paid their fair share of tax.
Assistant Treasurer Kelly O'Dwyer said the government had given extra powers to the tax office to investigate and prosecute people not paying their fair share of tax in Australia.
Ms O'Dwyer also flagged her support to stop workers on average incomes heading into the second-top tax bracket.
She said it was "extraordinary" to think such bracket creep could be allowed to occur.
"Just consider that - average income, second highest tax bracket - that's pretty extraordinary and we can't continue to have the tax burden fall upon people who are working hard to provide for their families," she told 2GB radio.
Federal shadow treasurer Chris Bowen said if the treasurer was serious about reform there would be another meeting planned this year and not February 2016.
"We've actually got economic policy paralysis in this country," Mr Bowen said in a statement.
"The more we hear from Malcolm Turnbull and Scott Morrison, the more it seems to be about working out the best way to sell a GST increase at the next election."
