If premiums for Nevadans covered by the Affordable Care Act increase substantially next year, most will still be able to get coverage for $100 a month or less because of a built-in buffer against insurance rate hikes written into the law, federal health officials said Wednesday.

Californians with Medicare coverage would no longer be surprised by huge medical bills stemming from “observation care” in hospitals under legislation that state lawmakers approved overwhelmingly last week and sent to Gov. Jerry Brown to sign into law.

The mixed results for Medicare accountable care organizations continued last year with fewer than one-third of them qualifying for bonus payments, the CMS said Thursday.

The Obama administration is fighting the notion that recent bad news for the Affordable Care Act marketplaces, including multiple insurers pulling out and reports of skyrocketing premium rates, will sink the exchanges.

Despite a slowdown in the growth rate of overall national health expenditures, Americans are seeing more of their paychecks go to health-care costs. The increase is largely thanks to cost-shifting through higher deductibles in plans offered by employers, which cover the majority of workers and their families. The trend has hit middle-income households the hardest. Here are five things to know about trends in U.S. health-care spending.

A new analysis predicts there will be 10.1 million people enrolled in exchange plans by the end of 2016, less than half of the number originally predicted by the Congressional Budget Office in 2010.