A controversial and costly proposal to create a government-run, single-payer health care system in California easily passed its first major hurdle Wednesday, despite a lack of details on how the state would pay for the ambitious program.

Under the proposed plan, everyone would be covered — from undocumented residents to Medicare and Medicaid recipients as well as employees who already get their health insurance through work.

In a 5-2 vote, the nine-member Senate Health Committee agreed to move Senate Bill 562 forward to the Senate appropriations committee, where key aspects of the plan must still be ironed out.

“Colleagues, let’s do something big for our state and our constituents,’’ the bill’s co-author Sen. Toni Atkins, D-San Diego, said Wednesday.

“Let’s solve one of the most problematic issues of our time.’’

Capping her plea at the end of the 2 1/2 hour meeting, was her co-author Ricardo Lara, D-Bell Gardens, who noted that the hard line Congressional Republican Freedom Caucus on Wednesday had approved a new plan to repeal and replace the Affordable Care Act.

“This is why we have this sense of urgency,’’ Lara told committee members before their vote, even as he acknowledged that the Healthy California Act must be done “correctly, with truth and honesty and be completely transparent to our California residents.’’

The plan, after all, would up-end traditional health insurance for the majority of California’s 39 million residents.

Senators Janet Nguyen, R-Garden Grove, and Jim Nielsen, R-Tehama, voted against the bill, while Senators Richard Roth, D-Riverside and Josh Newman, D-Fullerton, did not vote.

The proposal is similar to a single-payer health care system that liberals like Vermont Sen. Bernie Sanders have championed. But unlike unlike Vermont (population 620,000), where in 2014 a similar effort fell apart after the governor decided it would cost too much, proponents says California’s huge population is large enough to make the system successful here.

Single-payer systems essentially work 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.

The Healthy California Act 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 significant challenges remain, and chief among them is funding.

According to a 20-page committee analysis released Monday, the bill would cover 17.5 million Californians who have employer-based coverage; 11 million Medi-Cal enrollees; 4 million Medicare enrollees; 2.6 million individually insured residents and 3 million uninsured.

Lara and Atkins are relying on the federal government’s approval to divert $261 billion of federal dollars currently sent to California to pay for Medicaid, Medicare, and the Affordable Care Act, among other programs. Under this new program, that money would be set aside in a trust fund.

But the cost to cover everyone else who has employer-provided insurance would be staggering: about $58.3 billion in tax revenue, according to a UCLA Center for Health Policy Research study.

That could be a hard sell in the Legislature, however, where tax increases requires a two-thirds vote. And even if it did pass both chambers, there is no guarantee that Gov. Jerry Brown — already a skeptic on the funding — would agree to sign it into law.

“This plan could be over $200 billion in federal funds,’’ said Nguyen. “It will will exceed our state budget which is $124 billion.

“I believe everyone should have access (to healthcare),’’ she continued, “but I want to make sure we are not out there selling a plan to everybody… and then say, “Ooops.’’

Opponents — including health insurers, chambers of commerce, and healthcare companies like Oakland-based Kaiser Permanente — railed against the idea before the committee.

Teresa Stark, director of state government relations for Kaiser Permanente, said Kaiser has been providing “high quality health care’’ to millions over the decades. “Unfortunately, under this bill, we would not be able to do that,’’ she said. “Under this bill, Kaiser Permanente would be dismantled.’’

But Michael Lighty, director of public policy for the California Nurses Association/National Nurses United, which is sponsoring the bill, said a single payer — like Medicare — will ultimately save money.

By eliminating all private insurance premiums, deductibles and co-pays, and consolidating all existing sources of healthcare revenue, Lighty said, the proposed system would provide comprehensive benefits. He noted that those benefits would be “equal to or better than most employer sponsored plans,’’ including Medicare, Medi-Cal, Obamacare and children’s health insurance plans, but “at less cost.”

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.