INDIANOLA, Iowa — Senator Elizabeth Warren of Massachusetts said on Sunday that she would release a plan to finance “Medicare for all” in the coming weeks, bowing to critics who have pressed her to explain how she would pay for a single-payer health care system.
Ms. Warren has become known for her towering stack of policy plans, having offered dozens of proposals on a wide variety of subjects. But on health care, she has not been similarly forthcoming, and her repeated refusal to say whether she would raise taxes on the middle class to help finance Medicare for all has drawn sharp criticism from some of her Democratic presidential rivals.
Given her increasing status as a front-runner in the primary race, Ms. Warren was certain to continue facing challenges on the issue. For weeks, she has sidestepped questions about raising taxes, no matter who was asking and when. But it had been an open question whether it would remain politically tenable for her to continue simply aligning herself with Senator Bernie Sanders’s health care plan while declining to provide any detailed explanation of how she would pay for it.
Ms. Warren brought up the issue of Medicare for all at the end of a town-hall-style event in Iowa on Sunday afternoon. “I plan over the next few weeks to put out a plan that talks about, specifically, the cost of Medicare for all and, specifically, how we pay for it,” she told the crowd at the forum, held at Simpson College.
“This is something I’ve been working on for months and months, and it’s got just a little more work until it’s finished,” Ms. Warren added.
Speaking to reporters afterward, Ms. Warren did not directly answer when asked whether her financing plan would include taxes on the middle class.
Ms. Warren’s repeated refusal to explicitly say whether she would raise taxes on the middle class to help fund Medicare for all has stood in stark contrast to how she has talked about other policy areas — providing lengthy, detailed plans and explaining how she would create a tax on the wealth of the richest Americans to finance major proposals like student debt cancellation and universal child care.
On the subject of health care, Ms. Warren has locked arms with Mr. Sanders, of Vermont, declaring on the debate stage in June, “I’m with Bernie on Medicare for all.” But unlike Ms. Warren, Mr. Sanders has openly said that taxes would increase for the middle class.
Mr. Sanders’s plan would eliminate health insurance premiums and almost all out-of-pocket costs. But he would compensate by raising taxes, and his financing ideas include a payroll tax that would affect many middle-class Americans. Assessing the overall effects on individual Americans is not possible under his plan, because he has not been specific about the particular tax increases he would use.
“For virtually everybody,” Mr. Sanders said at last week’s debate, “the tax increase they pay will be substantially less — substantially less than what they were paying for premiums and out-of-pocket expenses.”
Ms. Warren has sought to reframe the question of raising taxes around the total costs that families would face under Medicare for all. She has said that costs would go up for wealthy people and big corporations, but would go down for middle-class families.
“I will not sign a bill into law that does not lower costs for middle-class families,” Ms. Warren said at the debate, a pledge she repeated in Iowa on Sunday.
The campaign of one of Ms. Warren’s top rivals, former Vice President Joseph R. Biden Jr., noted on Sunday that Ms. Warren committed to releasing a financing plan only after being pushed on the issue.
“It’s mystifying that for someone who has put having a plan for everything at the center of her pitch to voters, Senator Warren has decided to release a health care plan only after enduring immense public pressure for refusing to do so,” a spokesman for the Biden campaign, T.J. Ducklo, said. He added that the Biden campaign hoped Ms. Warren’s plan “will be straight with the American people about how much middle-class taxes will go up.”
When told that Ms. Warren said she would soon release a plan for financing Medicare for all, Mayor Pete Buttigieg of South Bend, Ind., replied: “Oh good. Well, she should.”
And Senator Amy Klobuchar of Minnesota offered a skeptical take about the coming plan. “I think if she had a good answer, we would have seen it by now,” she told reporters. “But I look forward to seeing it.”
Ms. Warren’s lack of specificity on paying for Medicare for all — and her consistent refusal to directly answer the question about raising taxes — has offered an opening for her opponents to criticize her.
Last month, Mr. Buttigieg called Ms. Warren “extremely evasive” on the subject, and at last week’s debate he pressed the point further, after Ms. Warren again avoided saying whether she would raise taxes on the middle class.
“We need to see how this is going to be paid for,” he said on Sunday on CNN’s “State of the Union” before Ms. Warren made her announcement, “because, right now, whether you copy-paste the Bernie Sanders math or do it some other way, there is a hole amounting to trillions of dollars in how this is supposed to work.”
Ms. Warren’s campaign had previously said that she was reviewing “revenue options” for Medicare for all. Ms. Warren did not provide details on Sunday about the contents of her forthcoming financing plan, and she noted that cost estimates for Medicare for all vary by trillions of dollars. “The different revenue streams for how to fund it, there are a lot of them,” she said.
Reid J. Epstein contributed reporting from Philadelphia and Margot Sanger-Katz from Washington.