The Tesla founder has previously warned that America was going “bankrupt” as a result of its US$36.2 trillion ($60.2t) debt pile, echoing similar concerns made by economists.
According to the Congressional Budget Office, Trump’s bill will increase America’s bulging deficit by US$3.8t by 2034.
It has drawn criticism from a number of Republicans, and the bill passed through the US House last month by just a single vote.
“It will massively increase the already gigantic budget deficit to US$2.5 trillion (!!!) and burden American citizens with crushingly unsustainable debt,” Musk added.
The White House has lashed out at anyone who has voiced concern about the debt snowballing under Trump.
“The President already knows where Elon Musk stood on this bill. It doesn’t change the President’s opinion. This is One Big Beautiful Bill, and he’s sticking to it,” Karoline Leavitt, the White House press secretary, said.
The tax and spending cuts that passed the House last month would add more than US$5t ($8.3t) to the national debt in the coming decade if all of them are allowed to continue, according to the Committee for a Responsible Federal Budget.
The national debt is a much bigger problem now than it was eight years ago. Investors are demanding the government pay a higher premium to keep borrowing.
The White House Council of Economic Advisers argues that its policies will unleash so much rapid growth that the annual budget deficits will shrink in size relative to the overall economy, putting the US Government on a fiscally sustainable path.
Central figure
Musk, 53, the world’s richest man, became a central figure in the Trump White House, often clashing with senior members of the President’s Cabinet.
The two quickly formed a close working relationship during last year’s election campaign. At its peak, Musk even lived in a cottage on the Mar-a-Lago estate where he fleshed out his plans for a tech-led effort to slash the federal bureaucracy.
He often stood quietly next to Trump as reporters peppered him with questions over his aggressive Doge cuts, which at times risked becoming the flashpoint of the President’s first 100 days in office.
Aside from the One Big Beautiful Bill, the Tesla boss has also voiced his concerns over Trump’s sweeping tariffs.
By the end of his time in the administration, he was rarely seen with the President.
Despite this, Trump has credited Musk with “a colossal change in the old ways of doing business in Washington” and handed him a golden key on his departure.
As a special government employee, Musk’s position was designed to be temporary. However, he had speculated about staying “indefinitely,” working part time for the administration, if Trump still wanted his help.
His departure from the White House last week marked the end of a turbulent chapter that included thousands of layoffs of federal staff and the evisceration of government agencies.
The billionaire entrepreneur is perceived as struggling in the unfamiliar environment of Washington, and he accomplished far less than he had hoped to.
He dramatically reduced his target for cutting spending – from US$2t ($3.3t) to US$1t ($1.6t) to US$150 billion ($249b) – and increasingly expressed frustration about resistance to his goals.
At times, he clashed with other top members of Trump’s administration, who chafed at the newcomer’s efforts to reshape their departments.
“Congress is making America bankrupt,” he wrote in a separate post on X.
