Biden and his wife, Jill Biden, reported taxable income of more than 900,000 U.S. dollars and paid nearly 300,000 dollars in taxes.
The couple also posted tax returns for 2016, 2017, and 2018.
Democratic vice presidential candidate and U.S. Senator from California Kamala Harris and her husband, lawyer Doug Emhoff, reported taxable income of more than 3 million dollars and paid nearly 1.2 million in taxes.
The release came two days after a New York Times investigation alleged that Trump paid just 750 dollars in federal income tax in both 2016 and 2017 and paid no taxes in 10 of the 15 previous years. The president has called the story "totally fake news."
A former business mogul, Trump has refused to release his tax returns, which are being sought by Democrats and state investigators, during his presidency, breaking a decades-old tradition maintained by his predecessors.
"Over the past decade, President Trump has paid tens of millions of dollars in personal taxes to the federal government, including paying millions in personal taxes since announcing his candidacy in 2015," Trump Organization lawyer Alan Garten said in a statement. "This is just part of the Times' ongoing smear campaign in the run up to the election."
Biden, former U.S. vice president and longtime U.S. senator, has emphasized the "Scranton vs. Park Avenue" message to appeal to working-class voters, which points to his Pennsylvania boyhood home and Trump's adult life in Manhattan, New York City.
The two candidates will meet in Cleveland, Ohio for the first 2020 presidential debate Tuesday night on topics such as their records, the Supreme Court, COVID-19, the economy, and race and violence in U.S. cities.
According to the RealClearPolitics polling average, Biden leads Trump by 6.1 percentage points nationally and 3.5 points in top battleground states, as of Tuesday. The gaps have been narrowing.