More key provisions of the the Affordable Care Act, also known as Obamacare, are slowly rolling into effect after being passed by the 111th Congress in 2010. Perhaps most controversial among them is the individual mandate.
The individual mandate, as associated by Obamacare, requires all U.S. citizens buy private health insurance or face a penalty, with some exemptions. Although Obama campaigned against the mandate during his 2008 campaign, the policy was ultimately added to the bill in order to ensure it passed.