SACRAMENTO – An ambitious proposal to create a single statewide insurance plan for every Californian — including undocumented residents, seniors on Medicare and people who now get their health coverage through work — began to take shape on Thursday when two legislators released details about what services would be covered and who would run the giant program.

Still missing, however, are the details that have bedeviled universal health care advocates for decades: how much it would cost taxpayers. And the plan will be difficult, if not impossible, to execute without permission from Washington to steer billions of federal Medicare and Medicaid dollars into a trust fund that covers everyone.

But advocates say it’s time for California to prove that a universal approach to health care isn’t just possible for the U.S., but also cheaper and less anxiety-inducing than the employer-based system now in place.

“I hope that people will have the vision and the guts to do it,” said Sheila Kuehl, a Los Angeles County supervisor and former state lawmaker who made numerous attempts to make universal health care the law of the land a decade ago, only to have the bills vetoed by then-Gov. Arnold Schwarzenegger.

A single-payer system generally works like this: Instead of buying health insurance and paying for premiums, residents pay higher taxes. And those taxes are then used to fund the insurance plan — in the same way Medicare taxes are used to provide insurance for Americans 65 and over.

With its simplicity, low overhead and cost controls, single-payer insurance “has the potential to create a lower cost health care system, so in total it could very well be that people in this state would pay less for health care than they do now,” said Larry Levitt, a senior vice president at the Menlo Park-based Kaiser Family Foundation.

One author of Senate Bill 562, Sen. Ricardo Lara, D-Bell Gardens, argues that the approach “covers more and costs less.”

“We have the chance to make universal health care a reality now,” Lara said in a statement about his bill, the Healthy California Act, which is sponsored by the California Nurses Association and a coalition of Californians and health care providers. “It’s time to talk about how we get to health care for all that covers more and costs less.”

The single-payer plan would be administered by a nine-member, unpaid board appointed by the governor and Legislature and a public advisory committee of doctors, nurses, health care providers and consumers. The board also would develop proposals related to long-term care, retiree health care and health care services covered under worker’s compensation.

But there are significant political hurdles. Experts say that unless the federal government allows California to funnel Medicare and Medicaid dollars into the system, it will be all but impossible to carry out.

And the health insurance industry, which would be upended by such a plan, has come out strongly against the bill and is expected to lobby aggressively against it.

“California led the pack in expanding quality health care to millions of residents over the past four years; we cannot jeopardize our progress by hastily instituting a failed model during this time of uncertainty,” Charles Bacchi, president and CEO of the California Association of Health Plans, said in a statement Thursday.

Advocates are also eyeing another challenge: the governor himself.

Jerry Brown rarely comments on current legislation, but he recently expressed deep skepticism.

“Where do you get the extra money?” Brown asked during a conversation with reporters last week during his visit to Washington, D.C., just before the GOP health care plan fell apart. “This is the whole question. I don’t even get. … How do you do that?”

The California proposal is similar in its goal to a single-payer health care system that liberals like Vermont Sen. Bernie Sanders have championed.

Proponents say that with its 39 million people, California is large enough to make the system work — unlike Vermont (population 620,000), where in 2014 a similar effort fell apart after the governor decided it would cost too much.

“I think that Bernie Sanders’ campaign last year indicated there was broader support for single-payer than a lot of people understood,” said Gerald Kominski, a professor of health policy at the UCLA Fielding School of Public Health. “This is an issue that’s not just going to go away.”

But one longtime critic of single-payer plans on Thursday called the Senate proposal “a budget buster.”

“This is a utopian socialist plan that will be very costly for the state budget and result in major tax increases for Californians, if passed and signed into law,” said Sally Pipes, president and CEO of the San Francisco-based Pacific Research Institute, a nonprofit that promotes limited government.

Pipes is originally from Canada, whose publicly funded health care system is viewed by some Americans as a model for the United States. But Pipes said the system has resulted in “rationed care” and growing wait lists to see a doctor.

One advocate for the single-payer approach, however, said he has one question for those who question its viability: “Why is it that every other country does it and it’s cheaper?” asked Andrew McGuire, founder and executive director of California OneCare, which is raising money to launch a campaign for the proposal.

KEY PROVISIONS OF THE HEALTHY CALIFORNIA ACT

The bill’s authors say their proposed single-payer system would include these features:

Coverage for all medical care, including inpatient, outpatient, emergency care, dental, vision, mental health and nursing home care.

No co-pays or insurance deductibles.

Ability to choose your own doctor from a huge list of health care providers rather than an insurer’s network.

The full bill is available at OnePlanMyChoice.com.

Source: Offices of Sens. Ricardo Lara and Toni Atkins.