A royal commission report to be released on Friday is expected to outline whether those involved in running the punitive scheme knowingly oversaw an unlawful program.
Mr Shorten, the minister now responsible for government services, said he wanted to see consequences for individuals the commission made adverse findings against.
"The maintenance of an unlawful scheme despite the farrago of complaints and the cacophony of unhappiness, the fact that they kept this freight train of misery going, someone's got to be responsible," he told ABC TV.
"There should be accountability."
Mr Shorten said he would refrain from commenting on individual cases to not prejudice any possible civil or criminal court actions.
He described it as a "huge day for the victims".
The inquiry, headed by former Queensland chief justice Catherine Holmes, was set up in August 2022 - three months after the Labor government was elected.
Mr Shorten confirmed the commissioner sought an extension to her reporting deadline so she could potentially refer cases and people to the federal anti-corruption watchdog.
Prime Minister Anthony Albanese said the government would take the time to give a "considered response" to the report.
"It should never have happened and the important thing is that it never happened again, because this was a human tragedy with real consequences for people," he told ABC radio.
"The cabinet has made a decision that will release it (the report) straight away so that the public can examine it."
Asked if a robodebt-style culture remained in other agencies, Mr Albanese said the government had put the "humans back into human services".
Opposition Leader Peter Dutton said he would wait and see what findings were made in the report.
"There is no question about why it's being dropped today," he told Nine's Today program, pointing to the upcoming Fadden by-election.
But Mr Shorten denied the report was being released early for political gain, saying it would be inappropriate for the government to sit on it.
He confirmed former senior ministers who wanted to challenge the findings would have access to taxpayer-funded legal advice.
"If you really want justice, then everyone's got be treated appropriately with precision, otherwise that would smack of politics," Mr Shorten said.
The inquiry looked at the establishment, design and implementation of robodebt, its outcomes and the use of third-party debt collectors.
The former Department of Human Services launched a scheme to "detect, investigate and deter suspected welfare fraud and non-compliance" in mid-2015 in an effort to save billions of dollars.
The scheme - which became known as robodebt - issued debt notices to people identified through a process called income averaging, which compared reported incomes with tax office data.
More than $750 million was wrongfully recovered from 381,000 people under the scheme.
Victims told the royal commission of their trauma and fear as they received notices and debt collectors made contact.
The inquiry also heard evidence of bureaucrats ignoring serious questions and advice about the legality of the scheme.
The scheme was ruled unlawful by the Federal Court in 2019.
A settlement of $1.2 billion was reached between robodebt victims and the then-government in 2020.
Former prime ministers Scott Morrison and Malcolm Turnbull gave evidence at the inquiry, along with ex-ministers Alan Tudge, Christian Porter and Stuart Robert.
Almost 200,000 people had their welfare debts wiped in October last year.
Mr Shorten has described the scheme as the nation's "greatest failure of public administration in social security".
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