WASHINGTON — For months, President Obama has marveled that the billionaire investor Warren E. Buffett pays a lower tax rate than his secretary, citing it as an egregious example of an unjust tax code. It turns out that another famous and well-compensated American does, too: Mr. Obama.

The president and his wife, Michelle Obama, reported adjusted gross income of $789,674 in 2011, and paid just over 20 percent of it in federal taxes, according to income tax returns and gift-tax returns released by the White House on Friday. The White House confirmed that Mr. Obama’s secretary, Anita Decker Breckenridge, paid a “slightly higher” tax rate than her boss in 2011, on a salary of $95,000.

That, said a spokeswoman, Amy Brundage, “is exactly why we need to reform our tax code and ask the wealthiest to pay their fair share.”

On Monday, at the president’s urging, the Senate will take up the proposed “Buffett Rule,” a minimum tax for the wealthiest Americans. In his references to Mr. Buffett and his secretary, Mr. Obama always notes that like Mr. Buffett, he has done well, does not need tax loopholes, and could afford to pay more.