President Donald Trump is expected to propose cutting $800 billion from Medicaid over 10 years in a budget plan to be released Tuesday that would slash spending on anti-poverty and other programs, US media reported.
The plans for the massive cut to Medicaid - which funds health care for low-income and disabled people - come as lawmakers from his Republican Party are battling to repeal and replace Obamacare, in which Medicare plays an important role.
The $800 billion cut to Medicaid is contingent on a health care bill passed in the House of Representatives earlier this month becoming law, The Washington Post on Sunday quoted people familiar with the plan as saying.
That bill to dismantle the Affordable Care Act - as former president Barack Obama's signature health care law is called - would cut federal support for Medicaid by more than $800 billion over a decade.
Medicaid's expansion under Obamacare extended health care coverage to some 11 million previously uninsured adults. Medicaid currently covers more than 70 million mainly low-income and disabled people.
The House bill would cut federal funding for the entire Medicaid program by 25 percent by 2026 and shift the burden to states, which would receive set amounts in the form of grants that would force them to reduce eligibility or cut benefits.
The American Medical Association issued a scathing criticism of the bill, warning that it would cause millions of Americans to lose their health care.
Some Republicans who also criticized the House bill say they oppose major cuts to Medicaid. The Senate is working on its own separate health care legislation.
The Congressional Budget Office, which appraised an earlier version of the House bill in March, said 14 million fewer people would enrol in the program by 2026.
The CBO is expected to release a new score of the revised bill on Wednesday.
Trump promised not to cut Medicaid during his campaign last year.
His comprehensive budget plan to be unveiled Tuesday will provide the most detailed look at his plans to overhaul government spending and taxes since he issued a blueprint in March.
It would make drastic cuts in spending on the arts, environmental protection and foreign aid, scrapping dozens of programs but making a large increase in military spending and border security, the Post reported.
Critics say the plans would amount to a massive boost for the wealthy.
"This budget continues to reveal President Trump's true colors," the Senate's Democratic leader Chuck Schumer said in a statement on Sunday.
"His populist campaign rhetoric was just a Trojan horse to execute long-held, hard-right policies that benefit the ultra-wealthy at the expense of the middle class."
Congress must approve most of the plan's changes before they can be enacted.