Health insurers are facing new rules and restrictions on how they set prices as part of the Affordable Care Act's aim to expand coverage to millions of Americans. No longer can insurers deny coverage because of a preexisting condition or place lifetime limits on medical care. While a person's age will remain a factor in setting rates, older customers cannot be charged more than three times what younger customers pay. California also has rejected an option under the federal law that allows health insurance companies to charge smokers up to 50 percent more for their premiums. All this leaves geography as one of the few ways insurers can adjust premiums. The premiums will not be set for most consumers under the law until summer, although estimates are available at the website of California's health benefits exchange.