On March 23, 2010, President Obama signed the Affordable Care Act. The law puts in place comprehensive health insurance reforms that will roll out over four years and beyond. The Affordable Care Act was put into place to ensure any and all residents of the United States qualify and receive medical health insurance. The Affordable Care Act has had some changes so please see the link below for an interactive timeline of changes from 2010-2014.
http://www.healthcare.gov/law/timeline/index.html