Existing sites in Ceduna in South Australia and WA's East Kimberley area will have their trials extended to June 2019. It comes just after the Nick Xenophon Team (NXT) and other crossbenchers supported the bill.
Under the scheme, 80 per cent of a welfare recipient's income is loaded onto a non-cash debit card which cannot be used to gamble or buy alcohol.
The NXT's lone lower house MP, Rebekha Sharkie voted against the bill last week, which then included rollouts in Hervey Bay and Bundaberg in Queensland.
"If the community has stepped up and asked for help, we should put politics aside and listen."
The NXT's crucial Senate voting bloc were expected to block the trial's growth, but compromised with the single expansion site in the Goldfields on Monday night.
Labor opposed any new trial sites, arguing there was insufficient evidence to show the existing trials were working.
"Labor requires a much more rigorous evaluation of the cashless debit card in the existing trial areas prior to any expansion," Labor frontbencher Doug Cameron told parliament.
He said the program had already cost $25.5 million - or $12,000 per participant - though the government argued most of that was due to one-off start-up costs.
Prime Minister Malcolm Turnbull said the card had made communities safer by addressing welfare-fuelled violence and misery.
"The cashless debit card is not for everyone but if the community has stepped up and asked for help, we should put politics aside and listen," Mr Turnbull said.
WA Greens senator Rachel Siewert said she had deep concerns with the NXT agreeing to expand the trial.
"I think it's a bit rich quite frankly for them to say 'oh yeah we'll support another trial site - make it in Western Australia'," Senator Siewert said.
Liberal frontbencher Concetta Fierravanti-Wells said research found the scheme had been effective in reducing alcohol consumption and gambling. KAP Federal Leader and Member for Kennedy Hon Bob Katter MP agrees and is pushing for the expansion of the Bill which he believes will deliver real outcomes for First Australian communities.
“The suicide rates in these communities, once again, are the highest in the world. You measure a nation by the way it treats its poorest people and its most downtrodden people," he said.
"If we're being judged by that then we are judged abominably and we must stand as a pariah amongst nations."
Crossbenchers David Leyonhjelm, who argued taxpayers didn't want their money to pay for other people's alcohol or gambling, Fraser Anning, Derryn Hinch and Cory Bernardi also supported the bill.
One Nation supported the scheme with leader Pauline Hanson channelling her 1996 maiden speech with claims of an "Aboriginal industry" in Australia's welfare system.