Vice President Harris has spent more than two years helping steer federal efforts to relieve the burden of medical debt — an initiative the likely Democratic nominee is touting as her presidential campaign takes shape.

The vice president’s work to combat medical debt, which has received scant attention compared with her work advocating for abortion access and other priorities, could emerge as one of her signature policy accomplishments as she challenges former president Donald Trump. About 100 million Americans are affected by medical debt, advocates and officials estimate, saying it is a pocketbook issue that influences whether to seek health care, purchase a home and make other major decisions.

“The Biden-Harris administration has done more to talk about medical debt than any other administration in history, and certainly Vice President Harris has really been at the forefront, often leading those efforts,” said Mona Shah, senior director of policy and strategy at the Community Catalyst Action Fund, a nonprofit health advocacy group.

Working with officials at the Consumer Financial Protection Bureau and other agencies, the Harris-led initiatives have sought to address a persistent problem that shadows patients with medical bills: the presence of unpaid medical debt on credit reports. As a result of those efforts, credit reporting agencies have removed medical bills from the credit reports of about 30 million Americans, a measure of relief even if patients still had to figure out a way to pay their debt.

The administration also is proposing federal rules to ban credit reporting agencies from incorporating medical debt when calculating credit scores and to block medical debt from being used to evaluate borrowers’ fitness for mortgages and other types of loans. That rule is expected to be finalized next year, if Harris is elected president.

The primacy of the issue was evident as recently as Wednesday, when Harris spoke to a national sorority convention in Indianapolis.

“We believe in a future where the economy works for working people,” Harris said. “We are finally making it so that medical debt can no longer be used against your credit score.”

While a record number of Americans now have health insurance, patient advocates warn that medical debt continues to be a source of financial distress.

“Our estimates are that for someone in the U.S. who gets a new cancer diagnosis, about 40 percent of them deplete their life savings almost in the first two years of cancer care,” said Karen E. Knudsen, chief executive of the American Cancer Society.

Some researchers have concluded that reducing or eliminating medical debt may have little impact on individual behavior and finances, noting that many Americans rarely repay long-lasting medical debt.

Benedic N. Ippolito, a senior fellow at the right-leaning American Enterprise Institute, testified to Congress this month that federal initiatives such as removing medical debt from credit reports could have “relatively muted” effects, and he cautioned against taking additional steps to change how medical debt is treated.

“Recent changes have already significantly reduced the impact of medical debts for many consumers,” Ippolito wrote in a text message to The Washington Post. “To me, there is a very strong argument for better understanding how these changes have played out before going further.”

Colleagues who have worked with Harris on the initiatives say the vice president’s focus on medical debt echoes her work on issues such as tackling student debt and the mortgage crisis as California attorney general a decade ago.

“I always see her thinking hard about the bills that consumers are facing, and what are the ways to lower those costs and how to make sure that debt is not blocking opportunities to advance the American Dream, especially when it comes to housing,” said Rohit Chopra, director of the Consumer Financial Protection Bureau.

Harris and her office are coordinating with North Carolina officials on a pilot project to forgive the medical debt of about 2 million people in that state. Under the proposed project, hospitals that take steps to relieve patients’ existing medical debt and adopt policies to prevent the accumulation of new debt would be rewarded with additional funding through the Medicaid program. Federal approval from the Centers for Medicare and Medicaid Services for the project is expected Friday, according to three people with knowledge of the matter, who spoke on the condition of anonymity to discuss forthcoming plans.

Federal officials declined to comment on the status of North Carolina’s request.

North Carolina Gov. Roy Cooper (D), who said he briefly discussed Harris’s work on medical debt with her when she visited his state this year, said he believed North Carolina’s plan could be “a really big deal — if it works.” Some hospitals have raised questions about the initiative, suggesting they may not participate.

“We think that if we can clear the deck with medical debt for low- to middle-income people, not only will that significantly relieve a burden for them, but it also can help make people healthier,” Cooper said. “They won’t have this fear of going to a doctor or going to a hospital if they needed.”

Cooper, who The Post has reported is being vetted by the Harris campaign as her potential running mate, declined to comment on the prospect of joining Harris’s presidential ticket.

“She has a lot of great people to choose from,” Cooper said. “I want her to pick the person that can help her win. I respect her process, and I don’t want to comment on that process.”

Harris has backed efforts to use funds from the American Rescue Plan to buy medical debt from health providers — an initiative on track to forgive $7 billion for 3 million Americans by 2026, the vice president’s office said Thursday.

Voters have repeatedly identified health-care costs as a priority ahead of this year’s presidential election. Seventy percent of adults said they worried about a medical or dental bill putting them into debt or worsening their existing debt, according to a poll released in February by KFF, a nonpartisan health-care research organization. Voters with financial struggles were more likely to say that Trump did more than President Biden to address health-care costs, the KFF poll found.

Democrats have increasingly highlighted the issue of medical debt. Sen. Bernie Sanders (I-Vt.) this month convened a Senate hearing on the goal of eliminating medical debt, and local officials in New York, D.C., and other communities have partnered with Undue Medical Debt, a charitable group focused on relieving debt.

Illinois Gov. J.B. Pritzker (D) — who has also been floated as a potential Harris running mate, The Post has reported — signed legislation this month that would forgive nearly $1 billion in medical debt held by state residents. Pritzker also signed a state bill to ban medical debt from being included on credit reports, mirroring the federal effort.

“This is just a very popular topic that we all have run out at the same time,” said Kody Kinsley, North Carolina’s health secretary.

Democrats’ efforts to crack down on medical debt have drawn some criticism from the financial services industry and parts of the health system, worried about unintended consequences.

The Biden administration’s plan to remove medical debt from credit scores “will increase the cost of medical care and force more upfront payments,” Scott Purcell, CEO of ACA International, the professional association for collection agencies, said in a statement last month. He added that reducing the incentive for people to pay their medical bills would harm health-care providers and “fundamentally alter the U.S. credit-based economy.”

Allies and staff say Harris’s interest in combating medical debt dates to her time as California attorney general, when she helped defend the Affordable Care Act and its coverage expansion from legal challenges. Harris also tackled student debt at for-profit colleges, suing the now-defunct Corinthian Colleges.

Chopra, who first worked with Harris when she was suing Corinthian, drew a comparison between medical and student debt, saying that a network of debt collectors and other companies have emerged to benefit from the explosion in both kinds of debt.

“We really see that medical debt bears some eerie similarities to the run-up in student debt over a decade ago,” he said, warning that both create a “domino effect” that can harm other financial decisions.

Harris in 2022 said she had “met so many people in so many communities in our nation who are struggling with this burden — many of whom are managing an illness or an injury at the same time and who stay up at night, staring at the ceiling, wondering if they will ever pay off their medical debt.”

North Carolina’s pilot program to combat medical debt was conceived by Cooper and his staff after the state expanded Medicaid last year, officials said. Health leaders also observed how other states such as Illinois and Tennessee had received federal approval to put Medicaid funds toward their own health improvement efforts, drawing on those examples as they proposed their new approach to reward hospitals for combating medical debt.

Kinsley, North Carolina’s health secretary, said he and his staff had coordinated their medical debt effort with Harris’s office, given her national attention on the issue.

“I think our approach they saw as kind of a novel one that other states hadn’t thought of and could potentially be a model,” Kinsley said.