The Supreme Court is set to soon decide on a challenge to the Obama administration's requirement that employers provide no-cost birth control. (Andrew Harrer/Bloomberg)

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Two Junes ago, we were waiting on a major Supreme Court decision on Obamacare. It's funny how history repeats itself.

Any day now, the high court is set to rule on challenges to the administration's requirement that employer health plans provide a wide range of birth control at no-out-of-pocket cost. The challenges, Sebelius v. Hobby Lobby Stores, Inc. and Conestoga Wood Specialties Corp. v. Sebelius, was were brought by two employers who argue the contraception mandate violates their religious freedom.

An adverse ruling against the contraception mandate wouldn't hurt the core of Obamacare, but it would be the first part of the law scaled back by the Supreme Court since it decided two years ago that the federal government couldn't force states to expand Medicaid. As we wait for a Supreme Court decision, here's a primer on the case.

What's the contraception rule?

The Affordable Care Act requires health plans to provide preventive benefits without cost-sharing, and the Obama administration in 2011 adopted an Institute of Medicine's recommendation that preventive benefits include a full range of Food and Drug Administration-approved contraception. When the requirement took effect in August 2012, the Obama administration said 47 million women were enrolled in health plans affected by the rule.

Facing pushback from Catholic groups, the administration in early 2012 offered a work-around for religiously affiliated organizations, like hospitals and colleges, that would allow their employees to obtain free contraception coverage directly from insurers. That carveout has also been challenged in the courts, but the Supreme Court case doesn't address the accommodation for these groups.

Who are the companies?

Hobby Lobby is a chain of craft stores owned by Evangelical Christians who say they run their business on Christian principles, and Conestoga is a Mennonite-owned company specializing in wood cabinets. The owners don't object to all types of birth control, but they're opposed to intrauterine devices and forms of emergency contraception, like Plan B and Ella. Dozens of other for-profit companies have also challenged the rule, but the court is only considering the challenge from these two.

What's at stake

This is the first time the court will consider whether the Constitution or the Religious Freedom Restoration Act, protecting an individual's exercise of religion, applies to for-profit companies and their owners. The RFRA, a 1993 law, says the government can't impose a "substantial burden" an an individual's religious exercise without a "compelling governmental interest" that's the least-obstructive way of achieving the government's goal.

Supporters of the contraception requirement argue that for-profit companies don't have the same religious protections as individuals and that the exemption would be a burden on workers who don't share their employers' religious beliefs. They've also made the slippery-slope argument: If employers can claim a religious exemption to providing contraception, can they also refuse to pay for other health-care services, like vaccines, on the same grounds? The companies argue that wouldn't be the case.

How did oral arguments go?

The Supreme Court justices "seemed sympathetic" to businesses' arguments, wrote the Washington Post's Supreme Court reporter Robert Barnes after the March 25 hearing. The five conservative justices appeared to agree that two companies could be covered by the federal law providing religious protections to individuals, and it seemed that Justice Anthony M. Kennedy will be the swing vote.

However, oral arguments aren't a reliable predictor of how the justices will decide. Consider that justices two years ago seemed ready to throw out Obamacare's individual mandate — perhaps the entire health-care law. And we all know how that turned out.

Does Obamacare still face any other legal challenges?

Yes, including one that would deal a potentially much bigger blow to the law. A few appellate courts, including the one in the District of Columbia, may soon decide whether people in 36 states with a federal-run exchange are eligible for premium subsidies. Some GOP lawmakers are also challenging a rule allowing members of Congress and their aides to receive subsidized coverage.

Top health policy reads from around the Web:

The concerning growth of the hospice industry. "What once was a collection of mostly small, religious-affiliated nonprofits is now a booming, $17 billion industry dominated by national chains. .. Nearly half of all Medicare patients who die now do so as a hospice patient — twice as many as in 2000, government data shows. But mounting evidence indicates that many providers are imperiling the health of patients in a drive to boost revenues and enroll more people, an investigation by The Huffington Post found." Ben Hallman in the Huffington Post.

Virginia governor steps up Medicaid fight. "Gov. Terry McAuliffe (D) vetoed portions of the state budget Friday, setting Virginia up for a legal showdown with legislative Republicans who oppose his efforts to expand Medicaid under the Affordable Care Act. McAuliffe exercised his line-item veto power to strike budget language that Republicans had hoped would block expansion of Medicaid." Laura Vozzella in the Washington Post.

California probes insurers' provider networks. "California regulators are investigating whether Anthem Blue Cross and Blue Shield of California have violated state law in connection to patients struggling to find doctors under Obamacare. Officials at the California Department of Managed Health Care said they are looking into whether consumers were misled by inaccurate provider lists and the difficulty some patients are still having at locating a physician in narrower networks statewide. Both Anthem and Blue Shield have acknowledged that mistakes have been made with respect to their networks and some confusion was inevitable during such a massive overhaul." Chad Terhune in the Los Angeles Times.