Bernie Sanders is a millionaire.

To celebrate, the Vermont senator says he plans to release 10 years' worth of tax returns by Monday, which just so happens to be Tax Day. Sanders, who officially announced his second run for the Democratic presidential nod last month and had been slow to release his most recent returns in 2016, goaded President Donald Trump to follow his lead.

"On the day in the very immediate future, certainly before April 15, we release ours, I hope that Donald Trump will do exactly the same," Sanders told The New York Times.

The Democrats' showcase legislation, HR 1, would require presidents, vice presidents and the major-party nominees for those offices to release 10 years' worth of tax returns.

Other 2020 Democratic hopefuls who have released either 2018 tax returns, or at least a decade of previous returns, include Sens. Kirsten Gillibrand of New York, Amy Klobuchar of Minnesota and Elizabeth Warren of Massachusetts as well as Gov. Jay Inslee of Washington.