Americans need to know more before they can make up their minds about proposed overhauls to the nation’s health care system, according to a survey released Thursday.

When asked if they wanted to wipe out private health insurance for a so-called Medicare for All public insurance program, 40 percent of U.S. adults between the ages of 19 to 64 said they did not know enough to offer an opinion.

A few Democratic presidential candidates have put forward their proposed health care plans, including Medicare for All. Sen. Bernie Sanders, I-Vt. and Sen. Elizabeth Warren, D-Mass. have advocated for Medicare for All models that replace private insurance with a national health insurance plan. And Sen. Kamala Harris, D-Calif., released a health care proposal that covered 330 million Americans under one government health care plan. According to the candidates, these plans would make health care affordable for more Americans. It could help reduce the number of uninsured Americans, which currently amounted to 27.5 million people nationwide in 2018, according to the Census Bureau, marking a rise of 1.9 million people over the previous year.

According to a July 22 poll from the PBS NewsHour, NPR and Marist, 70 percent of U.S. adults said they supported Medicare for All proposals as long as they maintain an option to keep private health insurance. A system like this has been proposed by Pete Buttigieg. By comparison, when asked in a separate question, only 41 percent of survey respondents said they wanted to scrap private health insurance for a government-run plan.

In this latest poll from the Commonwealth Fund, another 32 percent of Americans said they opposed the idea, while 27 percent of Americans favored such a plan, according to the survey results published by the Commonwealth Fund, which researches health policy. The survey polled 4,914 U.S. adults ages 19 to 64 from March 19 to June 9.

“People are confused about what this might mean for them, and what it might mean for the health system and what it might mean in terms of trade-offs,” said Sara Collins, vice president of Health Care Coverage and Access at the Commonwealth Fund, during a call with reporters Wednesday.

Americans are largely satisfied with their health insurance, but lacked confidence that their health care coverage could protect them financially if they fell seriously ill and required medical care.

“These satisfaction rates reflect the fact that most people don’t use their insurance a ton.”

“These satisfaction rates reflect the fact that most people don’t use their insurance a ton,” said Sabrina Corlette, a research professor and co-founder of the Center on Health Insurance Reforms at Georgetown University. “It’s sporadic interactions.”

Eighty-five percent of working-age Americans said they were satisfied with their health insurance. That included private health insurance, Medicaid, and coverage purchased on the individual marketplace established under the Affordable Care Act. Another 14 percent said they were dissatisfied with their current health insurance.

In contrast, 61 percent of U.S. adults age 16 to 64 said they were confident that they would be able to afford the cost of care if they became seriously ill, while 38 percent of Americans said they were not confident.

These survey results come as Democratic presidential candidates promote their health care plans going into the 2020 election. Meanwhile, Republicans in Congress and the Trump administration have promised to replace the Affordable Care Act, known as Obamacare, with “something better,” although it is unclear what that would be. To date, they have eliminated some policies put into place under Obamacare, including dismantling the individual mandate.

Health care will be one of the most important issues among voters going into the next presidential election. Health care costs for Americans are the highest among industrialized nations. Meanwhile, life expectancy has dropped nationwide in recent years, in part due to the rise in drug overdose deaths, many of which are tied to the opioid crisis. Among developed nations the OECD ranked for infant mortality, the U.S. was among the bottom 11, after Russia.

This survey suggests that all the campaigns have their work cut out for them if they want to ramp up public awareness of proposals on the table to fix health care, Corlette said. She said the public needs more education and discussion about possible solutions aimed at problems in the U.S. health care system.

“It strikes me as a really good opportunity for people on both sides of the debate,” Corlette said. “There’s clearly a lot of people who have just not made up their mind.”

“It’s important to remember that people need most of all economic growth, job security and reasons to be optimistic about managing their lives.”

But she said the lack of confidence in how much protection health coverage affords people tugs at the reality that “the system doesn’t work really well for people who are very sick.”

New analysis from the Kaiser Family Foundation supports that notion. Annual family premiums for employer-based health insurance rose 5 percent to $20,576 on average, faster than wage growth, which increased by 3.4 percent, according to the study, published in Health Affairs. And since 2009, those premiums jumped 54 percent.

Health insurance costs and coverage only provide part of the picture of what troubles Americans, said Thomas Miller, a resident fellow with the conservative American Enterprise Institute.

Policymakers need to think about more than tinkering with “incremental expansions of coverage on the margins beyond where we already are,” Miller said. “It’s important to remember that people need most of all economic growth, job security and reasons to be optimistic about managing their lives.”