WASHINGTON • President Joe Biden on Tuesday proposed new taxes on the rich to help fund Medicare, saying the plan would help to extend the insurance program’s solvency by 25 years and provide a degree of middle-class stability to millions of older adults.

In his plan, Biden is overtly declaring that the wealthy ought to shoulder a heavier tax burden. His budget would draw a direct line between those new taxes and the popular health insurance program for people older than 65, essentially asking those who’ve fared best in the economy to subsidize the rest of the population.

Biden wants to increase the Medicare tax rate from 3.8% to 5% on income exceeding $400,000 per year, including salaries and capital gains. The White House did not provide specific cost-saving estimates with the proposal, but the move would likely increase tax revenues by more than $117 billion over 10 years, according to prior estimates in February by the Tax Policy Center.

“This modest increase in Medicare contributions from those with the highest incomes will help keep the Medicare program strong for decades to come,” Biden wrote in a Tuesday essay in The New York Times. He called Medicare a “rock-solid guarantee that Americans have counted on to be there for them when they retire.”

Senate Minority Leader Mitch McConnell, R-Ky., was quick to dismiss the plan, telling reporters on Tuesday that Biden’s budget agenda “will not see the light of day.”

More than 65 million people rely on Medicare at a cost to taxpayers of roughly $900 billion every year. The number of Medicare enrollees is expected to continue growing as the U.S. population ages. But funding for the program is a problem with federal officials warning that, without cuts or tax increases, the Medicare fund might only be able to pay for 90% of benefits by 2028.

Biden’s suggested Medicare changes are part of a fuller budget proposal that he plans to release on Thursday in Philadelphia. Pushing the proposal through Congress will likely be difficult, with Republicans in control of the House and Democrats holding only a slim majority in the Senate.

The proposal is a direct challenge to GOP lawmakers, who argue that economic growth comes from tax cuts like those pushed through by former President Donald Trump in 2017. Those cuts disproportionately favored wealthier households and companies. They contributed to higher budget deficits, when growth failed to boom as Trump had promised and the economy was then derailed in 2020 by the coronavirus pandemic.

The conflicting worldviews on how taxes would impact the economy is part of a broader showdown. Biden and Congress need to reach a deal to raise the government’s borrowing authority at some point this summer, or else the government could default and plunge the U.S. into a debilitating recession.

Grover Norquist, president of Americans for Tax Reform and an advocate for the kinds of tax cuts generally favored by Republicans, said that the U.S. economy would suffer because of the president’s plan.

“The Biden tax hikes will raise the cost of goods and services for everyone, and make American workers and businesses less competitive internationally and vs. China,” Norquist said.