A UCLA Center for Health Policy Research report showed that 670,000 Californians lost employer-based health insurance in 2008 and 2009. That is a far cry from the earlier estimate of 2 million newly uninsured in the state. But what’s interesting about the new number, according to the report’s lead author Shana Lavarreda, is that it indicates that a new class of uninsured has been rising.

“The uninsured here is less and less an undocumented [worker] problem, and now it’s more of a Main Street problem,” Lavarreda said.

A majority — if not all — of those working-age Californians who lost coverage over that two-year period could have been considered residents of “Main Street.”

“That big increase was almost completely due to the people who lost their jobs, and so lost their health insurance.”

The rate of population growth in California has declined in the past three years, she said. The large population of undocumented workers here has traditionally meant a rise in uninsured numbers, but “the new projection for the number of the [uninsured] undocumented actually shrank,” Lavarreda said. “It went down. So the increase is more of a mainstream problem.”

The rise in mainstream uninsured could have a significant impact on portions of the Affordable Care Act scheduled to take effect in 2014. Increased demand also shows the need for the ACA, Lavarreda said.

“It definitely establishes a higher baseline than they had when the ACA was first passed,” she said. “That adds a great deal of pressure onto the state. And it also raises the question of who’s going to provide care, because just having that many new people in the system is going to be a big challenge. It highlights that the problem is even worse than they thought when they passed the ACA.”