<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> The Patient Protection and Affordable Care Act, often shortened to the Affordable Care Act (ACA) or nicknamed Obamacare, is a United States federal statute enacted by the 111th United States Congress and signed into law by President Barack Obama on March 23, 2010 . The term "Obamacare" was first used by opponents, then reappropriated by supporters, and eventually used by President Obama himself . Together with the Health Care and Education Reconciliation Act of 2010 amendment, it represents the U.S. healthcare system's most significant regulatory overhaul and expansion of coverage since the passage of Medicare and Medicaid in 1965 . </P> <P> The ACA's major provisions came into force in 2014 . By 2016, the uninsured share of the population had roughly halved, with estimates ranging from 20--24 million additional people covered during 2016 . The increased coverage was due, roughly equally, to an expansion of Medicaid eligibility and to major changes to individual insurance markets . Both involved new spending, funded through a combination of new taxes and cuts to Medicare provider rates and Medicare Advantage . Several Congressional Budget Office reports said that overall these provisions reduced the budget deficit, that repealing the ACA would increase the deficit, and that the law reduced income inequality by taxing primarily the top 1% to fund roughly $600 in benefits on average to families in the bottom 40% of the income distribution . The law also enacted a host of delivery system reforms intended to constrain healthcare costs and improve quality . After the law went into effect, increases in overall healthcare spending slowed, including premiums for employer - based insurance plans . </P>

When did the affordable healthcare act go into effect