More than 16 million Americans have gained insurance coverage as a result of President Obama’s health care law, the administration said as the White House prepares to commemorate the fifth anniversary of the law’s signing, the AP reports.

“Most of those gaining coverage — 14.1 million adults – got their insurance after the law’s big expansion began at the end of 2013. Another 2.3 million people had gained coverage previously. Those were young adults allowed to remain on a parent’s plan until age 26 under one of the law’s most popular provisions.”

The Supreme court heard arguments on a second major challenge to President Obama’s healthcare law, “but no clear majority was immediately apparent in the case that takes aim at a pivotal part of the statute providing tax subsidies to help people afford insurance,” Reuters reports.

New York Times: “As expected, the court’s four liberal members voiced strong support for the administration’s position. But the administration must almost certainly capture the vote of either Chief Justice John G. Roberts Jr. or Justice Anthony M. Kennedy to prevail. The chief justice said almost nothing.”

A decision is due by the end of June.

Steven Brill: “Congress knew exactly what it wanted to do when it passed the Affordable Care Act in 2010, and contrary to the plaintiffs’ claim, that included wanting subsidies for buying health insurance on the Obamacare exchanges to be available to all citizens, even those residing in the 36 states that did not set up their own exchanges, instead relying on the exchange set up by the federal government.”

“I’m a reporter. I hate to take sides… But this is one of those issues where reporters err if they write an ‘on the one hand, on the other hand’ story that creates patently false equivalency.”

“I know what the legislators intended because in researching my book, I interviewed pretty much everyone involved in the conception and writing of the law. Moreover, I did that long before King v. Burwell had become the Obamacare opponents’ favorite new weapon, which means that those opponents had no reason to spin the fairytale that Congress did not intend for those subsidies to go to the millions of Americans signing up on the federally run exchange. At the time, no one had a dog in a fight over congressional intent, because there was no fight.”

Think Progress gives odds on how each Justice will vote.

Joshua Green: “The possibility that the U.S. Supreme Court will soon eliminate federal subsidies for people buying health insurance through the Affordable Care Act is the biggest story in politics and economics that no one wants to talk about. But the stakes in King v. Burwell, which the court will hear on March 4, could scarcely be higher: If the plaintiffs prevail, millions of people in 34 states who bought insurance on federal exchanges would suddenly lose the subsidies that make it affordable. Consequently, most would lose their coverage.”

“The immediate effect of a ruling against the ACA would be to hurl the political system, and no small part of the economy, into chaos. Yet there’s little sign that Washington is preparing for that scenario. Democrats won’t talk about what they would do because they don’t want the court to believe they could contain the fallout. Republicans don’t want to talk because they’re loath to admit that, even after voting 67 times to repeal or defund the ACA, they have no plan to help the millions who would be affected.”

Wonk Wire: Indifference to the Obamacare ruling from many governors

“The Obama administration said it would allow people to sign up for plans on HealthCare.gov through April to avoid tax penalties for going uncovered in 2015,” the Wall Street Journal reports.

“The extension, which adds more than two months to the enrollment period for health coverage this year, was announced by Health and Human Services officials on Friday.”

“The Supreme Court could be months away from blowing a huge hole in Obamacare — and Republicans on Capitol Hill are at odds over how they’ll respond if their side wins,” Politico reports.

“If they simply ‘fix’ Obamacare, they‘ll anger their right wing that wants the party to focus solely on repealing the law. If they do nothing, they invite blame for making health care unaffordable for millions of Americans — including some of their own constituents.”

Wonk Wire: Obamacare will cost $600 million less than previously expected

“Republicans are shifting their tactics on Obamacare, an abrupt change from the party’s “repeal-only” rhetoric that dominated the last five years of debate,” The Hill reports.

“The GOP is coalescing around the idea that incremental changes, rather than a sweeping repeal effort, can be more appealing to voters – while also holding out the possibility of hollowing out the law from within.”

“Elizabeth MacDonough holds no elected office. Few people outside of Capitol Hill even know her name. And forget about knowing her political leanings or loyalties. But she may very well be the most powerful person in Washington in determining how far Republicans can go in trying to repeal Obamacare,” Politico reports.

“As the Senate parliamentarian, MacDonough will make the decisions on which pieces of the law qualify to be repealed using a complicated budget procedure called reconciliation. Her decisions would allow Senate Republicans to vote to kill major provisions of the health care law under a simple 51-vote majority without giving Democrats a chance to filibuster.”

Wonk Wire: Republicans united on the politics of Obamacare

Jonathan Gruber, the health economist whose incendiary comments about “the stupidity of the American voter” have embarrassed the Obama administration, apologized for what he described as his “glib, thoughtless and sometimes downright insulting comments,” the New York Times reports.

Said Gruber: “I am not a political adviser nor a politician.”

Gruber also minimized his role, saying he had used an “economic microsimulation model” to help the administration and Democrats in Congress assess the impact of policies in the Affordable Care Act.

“The GOP is refocusing its attention on the courts as it searches for any way to weaken President Obama’s signature healthcare law while he continues to wield a veto pen,” The Hill reports.

“The reach to the Supreme Court is part of a flurry of recent legal action that reflects a growing consensus within the GOP that the party must rely on courts instead of Congress to strike down ObamaCare, especially as more pieces of the law are put into place.”

Wonk Wire: Where are the soaring health care costs?

“I would assume you could have a mulligan here, a major do-over.”

— Sen. Mitch McConnell (R-KY), quoted by the Wall Street Journal, suggesting a major revamp of national health care legislation if the Supreme Court rules against a key provision of Obamacare.