The Supreme Court's validation of President Barack Obama's landmark health law sets off a scramble up and down California to find enough primary care doctors and other professionals to serve an estimated 3million newly insured patients by 2014.

California already rates below average in the number of doctors per capita.

But the state - rural and inland counties in particular - will face additional headwinds as health reform slashes the ranks of its 7 million uninsured.

California has an unusually large number of doctors heading into retirement years. It expects a much higher-than-average rise in the health-intensive 65-and-older population. And it has one of the lowest reimbursement rates in the country for Medi-Cal, the state's primary program offering health coverage for the poor.

Especially for communities already struggling with doctor shortages, the court's somewhat unexpected endorsement of the Affordable Care Act suddenly presents a steep challenge.

"The Affordable Care Act will add hundreds of thousands of people to the rolls of the insured. That's good," said Dr. G. Richard Olds, founding dean of the UC Riverside School of Medicine. "But where are the primary care physicians going to come from to serve that population?"

According to a 2009 study by the California HealthCare Foundation, only 16 of 58 California counties had sufficient primary care doctors as measured against standards set by the American Medical

Many of California's most acute shortages are in the Inland Empire and the San Joaquin Valley, where communities struggle to attract and retain doctors. They also have some of California's highest uninsured rates - exceeding 30 percent of residents in some counties, according to a 2009 UCLA study.

That could mean the same counties already fighting doctor shortages could see big increases in the insured starting in 2014.

Asked if local providers in San Luis Obispo County were numerous enough to accommodate the new patients created by health reform, county health officer Dr. Penny Borenstein had a definitive answer: "No. Simply."

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Next health care headache: Shortage of doctors