After the Massachusetts senator blasted the tax code for being “rigged” and asking to change it “so The Person of the Year will actually pay taxes and stop freeloading off everyone else,” Musk tweeted that he’s contributing more than any other U.S. citizen this year. 

Musk’s tax bill for 2021 could exceed $10 billion if he exercises all his options due to expire next year, according to Bloomberg calculations. While it’s hard to say whether that would be a record, it’s certainly one of the biggest payments.

Since a Twitter poll last month where he asked whether he should sell 10% of his Tesla stake, Musk has exercised almost 15 million options and sold millions of shares to cover the taxes related to the transactions. 

Musk has previously used Twitter to berate senators Bernie Sanders and Ron Wyden over their support for a tax on billionaires.