In California, it is not unusual for patients to be hit by large, unexpected medical bills when they are unwittingly treated by someone outside their insurance company’s network.

Changes in the way small and mid-sized companies are regulated by the Affordable Care Act could make a substantial difference to more than half of Orange County’s workers and their families — and both they and their employers could benefit.

State health insurance exchanges created under the new health care law are in turmoil. By contrast, the employer market — where the majority of Americans still get their coverage — seems like a bastion of stability.

The number of Americans without health insurance declined to 9.1 percent last year, according to federal data released Tuesday. A set of maps released by the Census Bureau suggests an obvious way to decrease the uninsured rate even more: expand Medicaid in the 19 states that haven't.

The dozen ObamaCare exchanges run by the states are struggling financially and could be headed toward collapse over the next several years, according to a new report released Tuesday by House Republicans.

Early in August commercial health insurer Humana Inc. disclosed it was joining a growing list of big insurance companies scaling back participation in public health exchanges.