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What you need to know about proposed changes to Medicaid

About half of the Saban Community Clinic's 18,000 patients were uninsured prior to the Affordable Care Act. Almost all of those patients qualified for Medi-Cal after the health law expanded eligibility. Maya Sugarman/KPCC

The Republicans' health insurance legislation includes big changes to the way the federal government would pay for Medicaid, the health-care program for the poor.

Here's what the bill would mean for Medi-Cal, as the program is called in California.

How many people are on Medi-Cal?

More than 13 million people were on Medi-Cal as of December 2016, according to the state Department of Health Care Services.

Who is eligible for Medi-Cal?

Medi-Cal has always covered disabled persons, low-income children, pregnant women and families.

In 2014, under the Affordable Care Act, California expanded Medi-Cal eligibility to include low-income, childless adults who make less than 138 percent of the poverty level. That means an individual has to make less than $16,395 a year to qualify.

About 27 percent of those enrolled in Medi-Cal received insurance through the Medicaid expansion, according to Health Care Services.

How is Medicaid funded?

Currently, the Medicaid program is jointly funded by states and the federal government.

For some expenditures, the federal government guarantees states at least $1 in federal funds for every $1 in state spending.

"This open-ended financing structure allows federal funds to flow to states based on actual costs and needs as economic circumstances change," the Kaiser Family Foundation explained in a May 2015 policy brief.

In some cases, Medicaid provides a higher matching rate, like for those who obtained coverage through the Medicaid expansion, according to the Kaiser Family Foundation. For those people, the federal government paid 100 percent of costs from 2014 to 2016; and it was expected to pay 90 percent starting in 2020 and thereafter.

How would Medicaid funding change under the GOP plan?

There would be at least two significant changes: Starting in 2020, the federal government would only contribute 50 percent of the cost of treating low-income adults who enroll in Medi-Cal under the Medicaid expansion.

On top of that, Washington would stop making an open-ended contribution for all Medicaid enrollees. Instead, it would cap the amount it pays per enrollee based on how much the state spent and how many people were in the program in the fiscal year that ended in 2016. That amount would increase slightly each year based on the medical care component of the consumer price index, but analysts expect it would not keep up with the actual growth in health care costs.

The cap would remain, even if the program faces unforeseen costs from an epidemic, an aging population or an expensive new treatment.

I got Medi-Cal through the Medicaid expansion. How would this bill change my access to health care?

We don't yet know how much money California would receive for Medi-Cal under the GOP formula, but experts expect the state would come up short.

In good economic times, the state could "weather the storm, where they're able to come up with ...  the additional match that's required to keep the Medicaid program going," said Dylan Roby, an assistant professor at the University of Maryland School of Public Health.

But in an economic downturn, "you could see a world in which they don't have enough tax dollars to come up with the state's share of the Medicaid program," he said, "and in that case, they would probably reduce eligibility levels, they would reduce benefits, they might lower the rates going to managed care plans or to providers."