In an early and major step toward implementing the federal health reform bill, about half a million low-income Californians will soon be eligible for benefits that are expected to address their health problems before they reach an emergency room.

Single childless adults with incomes up to about $14,500, who up until now have depended largely on emergency rooms for their care, will be moved into the health care system with a basic package of benefits paid for with an increase in federal funding.

They will have their own primary care doctors and a network of specialists to consult for complicated problems. Most importantly, they will have someone watching over and coordinating their care instead of jumping from doctor to doctor with little or no preventive care and no one knowing whether the treatment the patient is getting is making them better.

Toby Douglas, director of the state Department of Health Care Services, said the change will be profound for people who until now have been largely left to fend for themselves. Unlike low-income people with children, childless adults do not qualify for the state Medi-Cal program, no matter how poor they are.

“If these people get care now, it is episodic,” he said. “They go in, receive their care, there is no follow-up after that, no medical home they are assigned to.”

The new federal law calls for moving this population into the Medi-Cal program in 2014, with the federal government paying most of the cost of the expanded eligibility. But the law also allowed the states to move more quickly, as long as they met certain standards, with the federal government paying its normal share, about half of the costs.

Among the conditions: the networks of doctors and hospitals have to be large enough to ensure that patients could find medical help nearby, and get appointments within a certain amount of time. Each person must also be assigned a primary care doctor whose office will coordinate care among specialists, labs and hospitals.

The state is expecting about $3 billion in new federal money over a five-year period to pay for the program.

As part of the deal, the federal government is expected to waive some rules and regulations so that the state, through the counties, can implement the program with more flexibility. Each county will decide, within limits, what benefits it will offer, who will be eligible and how much doctors and hospitals will be paid.

The first ten counties to implement the changes have already been offering similar benefits under another program that began last fall. Those counties are expected to join the new program in the coming weeks, as soon as contracts between the state, the federal government and the counties can be ironed out.

The experience of Orange County shows what can happen when patients get preventive care and someone to coordinate their services.

Since it began the program, Orange County has seen a 48 percent reduction in unnecessary emergency room visits among this population, and a 47 percent reduction in the number of hospital days, according to Ronald Norby, deputy director of the county’s health care agency.

Under the new program, counties such as Orange that are already participating will simply have to tweak the benefits they offer, including more mental health coverage, for example, and podiatry. But the new federal money will also allow the county to pay doctors more, which will broaden the network; pay hospitals more, so they don’t have to shift as much cost to privately insured customers; and offer care to more people.

For many California counties that have not been serving this population at all, Norby said, the change will be “huge.”

In addition to Orange, the first counties to implement the program will be Alameda, Contra Costa, Kern, Los Angeles, San Diego, San Mateo, San Francisco, Santa Clara and Ventura.

Douglas, the state health services director, said he expects every county in the state to be in the program by the end of this year.