Proposed changes to the Medicare surcharge levy will be debated in the Senate on Tuesday after being passed by the lower house on Monday night.
The Rudd government's hopes of getting the changes through the Senate have also been given a boost after Family First Senator Steve Fielding said he would no longer stand in the way.
Senator Fielding had voted with the opposition to kill the government's original bill.
The Medicare bill in its original form would have raised the income thresholds at which the surcharge was applied for people without private health insurance from $50,000 to $100,000 for singles and from $100,000 to $150,000 for couples.
Last month, the government introduced a revised bill lowering the threshold for singles to $75,000.
Senator Fielding had also opposed the revised bill.
But Senator Fielding on Monday announced a surprising backflip, also saying he would now support an increase in the tax on alcopops, due to the threat posed by the global financial crisis.
"We've put the national interest first, as well as family first," Senator Fielding said.
"At the end of the day, if the economy goes down the gurgler, then families are going to be severely worse off."
However, the government still faces a hurdle in the Senate in terms of the changes to Medicare surcharge levy with Independent Senator Nick Xenophon saying he was not yet ready to declare support for the revised thresholds.
Senator Xenophon said he would move an amendment to have the thresholds set at levels equivalent to them having been indexed to inflation since the tax's introduction in 1997.
The bill passed the lower house 73 votes to 53 and will go to the Senate for debate on Tuesday.