Gov. Jerry Brown's administration vowed Thursday to continue pushing forward elements of the federal health care overhaul in California, even if the U.S. Supreme Court strikes it down.

If the court does rule the federal law unconstitutional, state Health and Human Services Secretary Diana Dooley said California should at least consider enacting its own universal health care legislation, including requiring every Californian to buy insurance.

"I think that we should be committed to making this system more rational than it is today, and improving the health of the people of California," Dooley said in an interview. "If we ask the insurance plans to take everybody and insure everybody with no screens or pre-existing conditions, then we have to have everybody buying some level of health insurance to meet their responsibility to the system."

She said whether the administration sponsors such legislation would depend on "where we are and what the conditions are at that particular time."

Dooley's remarks came a day after the Supreme Court finished three days of oral arguments over President Barack Obama's signature health care law.

At issue is whether Congress can require people to buy insurance and, separately, whether lawmakers overstepped in pressuring states to expand Medicaid coverage.

In 2010, California, amid urging from the White House, became the first state in the nation to enact legislation establishing a public health insurance marketplace to implement the Affordable Care Act.

The insurance exchange is expected to serve more than 2 million Californians beginning in 2014, many of them now uninsured residents who do not qualify for existing public health care or cannot afford coverage on the open market.

Through Medi-Cal, the state's version of Medicaid, California provides coverage for nearly 8 million low-income residents, including children and their parents, disabled individuals and the elderly. A separate program, Healthy Families, serves 878,000 children up to age 19 whose families earn too much to qualify for Medi-Cal.

Under the federal health care overhaul, the federal government would cover most costs for new enrollees such as single adults and parents who cannot qualify for Medi-Cal. From 2014 to 2019, California could receive $45 billion to $55 billion from the federal government, while the state would contribute an additional $3 billion to $6.5 billion, according to the Kaiser Commission on Medicaid and the Uninsured.

"Just from her (Dooley's) point of view, from the agency she manages, it's an infusion of literally billions of dollars into our health care system and our economy that is pending here," said Anthony Wright, executive director of Health Access California, an advocacy group.

Wright said an insurance exchange without federal subsidies "could still provide an easy, consumer-friendly marketplace that doesn't exist now in a very complex and confusing world."

But compared to the promise of the federal health care law, he said, "it won't be the same thing."

He said "there are some portions of the reforms that we can go forward with" but that "the key thing is money."

The California health exchange would bring together private insurers to serve new health care enrollees, subsidized by those federal and state dollars.

But it is difficult to know how any part of the program will fare until the Supreme Court reaches a decision, expected by the end of June.