One of the central planks of Obamacare was the individual mandate -- the requirement for every American to buy health insurance. Those who didn't would be required to pay a fine, ostensibly to cut down on free riders who'd refuse to pay for insurance and then stick taxpayers with the emergency room bill when they got sick. But thanks to a series of exemptions that have pushed wide swaths of Americans out of the reach of the individual mandate, almost 90 percent of uninsured Americans won't be forced to pay a fine in 2016, the Wall Street Journal reports.