Elizabeth Warren on Friday released her long-awaited plan to finance "Medicare for All" after pressure from some of her Democratic presidential rivals to explain how she'd pay for the single-payer health care system.

The Massachusetts senator said she'll pay for the estimated $20.5 trillion in new spending without raising taxes on middle-class Americans "by one penny." Instead, Warren's plan will place the burden on big corporations and the wealthiest in the country.

Warren, who's one of the front-running candidates for the Democratic nomination, said her plan provides "identical" comprehensive coverage like the Medicare for All plan proposed by Sen. Bernie Sanders of Vermont, which she has co-sponsored. But Sanders himself has acknowledged that taxes will need to increase for the middle class in order to pay for a government-run health care system.

And like Sanders has noted, Warren argues that families will ultimately save money on health care since Medicare for All eliminates costs associated with private insurance including premiums, deductibles and other out-of-pocket expenses.

Warren's campaign says her plan requires $20.5 trillion in new revenue and about half of that – $8.8 trillion – will come from employers, who are already paying private insurance companies for their employees' health coverage. Instead, Warren would have that money from companies go to the federal government "in the form of an Employer Medicare Contribution."

The senator from Massachusetts says the rest of that money would be paid through "targeted defense spending cuts, new taxes on financial firms, giant corporations and the richest 1% of Americans – and by cracking down on tax evasion and fraud.

Warren has already released an ultra-millionaire tax but says she's going a step beyond that by further taxing billionaires. Her plan would make billionaires pay an additional 3 cents on every dollar of net worth over $1 billion. She argues that the new tax could raise another $1 trillion in revenue.

"My plan reflects careful, detailed analyses from key national experts in health policy, tax policy, and economics," Warren said in her proposal. "By filling in the details, we can strip away all the misleading political attacks and make plain the choice facing the American people."

Warren said she plans to announce another proposal on the timeline for the implementation of her plan in the coming weeks. Sanders' Medicare for All legislation proposes a four-year transition.

Some of Warren and Sanders' more moderate opponents have continued to attack the progressive senators over Medicare for All, which essentially eliminates private insurance. Among others, former Vice President Joe Biden and South Bend, Indiana, Mayor Pete Buttigieg have instead embraced some sort of public option that expands on former President Barack Obama's health care law, the Affordable Care Act, and keeps private insurance intact for now.

Warren's opponents have accused her of being evasive when asked how to pay for Medicare for All. And Buttigieg, who has proposed a "Medicare-for-all-who-want-it" plan, argued at last month's Democratic primary debate that Americans should have a choice – whether that means enrolling in a public plan or staying on their private insurance.

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Warren has pushed back on those arguments, saying she won't "embrace a plan for 'Medicare for all who can afford it.'"

Following the announcement of Warren's funding proposal, Biden's campaign released a statement that the senator's plan "would place a new tax of nearly $9 trillion that will fall on American workers," referencing Warren's "Employer Medicare Contribution."

Biden's campaign also raised concerns about a "complete revamping of defense, immigration, and overall tax policy all at once" to help pay for Medicare for All.

"By putting forward an unrealistic plan, she will be left with only two choices: even further increase taxes on the middle class or break her commitment to these promised benefits," Biden deputy campaign manager Kate Bedingfield said in a statement.