More than $110 million of Medicare rebates is sitting unclaimed because some Australians have not provided their bank account details to the government.
Human Services Minister Michael Keenan says about 670,000 people are owed money, despite Australians being "constantly" reminded to update their details.
Changing the details takes just a couple of minutes and will allow thousands of people to get a "handy financial windfall", he said.
"The coalition government would much rather see this money sitting in your pockets instead of ours, which is why we are again reminding those who haven't given Medicare their bank account details that they need to take action now," the minister said on Thursday.
Labor human services spokeswoman Ed Husic said the government is wrong to blame average Australians for the rebates it hasn't paid out.
"The Morrison government has yet again failed to design a system to serve Australians - and when these failures become apparent they blame citizens," he said.
The average amount owed to each person is about $150.
But people could be in line for far more cash if they see their doctor regularly or are receiving treatment for a serious medical condition.
The $110 million makes up less than 0.5 per cent of the total Medicare benefits paid each year.
