The 77-year-old's tax documents confirmed Sanders is a millionaire, who made more than $1 million in 2016 and 2017. His adjusted gross income in 2018 was $561,293, and he paid a 26 percent effective tax rate.
"That's a lot of money ... it came from a book that I wrote. [It's] a pretty good book, you might want to read it," said Sanders during the opening of the town hall, adding that he wasn't going to apologize for having a best-seller.
Fox News anchor Bret Baier noted that Sanders benefited from Trump's tax bill, while Sanders pointed out that he voted against it.
"In my view ... wealthy people and large corporations that are making billions in profits should start paying their fair share of taxes," the 2020 presidential hopeful added.
Baier asked Sanders why he's holding onto his wealth rather than refusing deductions or writing a check to the Treasury Department, citing the senator's newly proposed 52 percent "wealth tax" that he advocated imposing on the nation's richest individuals.
"Pfft, come on. I paid the taxes that I owe," Sanders replied, laughing.
Sander then demanded that the correspondents call on Trump to release his tax returns.
"Hey, President Trump, my wife and I just released 10 years. Please do the same. Let the American people know," he continued, as the audience applauded.
Fox News' Gregg Re contributed to this report.