The Patient Protection and Affordable Care Act (PPACA), 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. 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.
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 to 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.
The act largely retains the existing structure of Medicare, Medicaid, and the employer market, but individual markets were radically overhauled around a three-legged program. Insurers in these markets are made to accept all applicants and charge the same rates regardless of pre-existing conditions or sex. To combat resultant adverse selection, the act mandates that individuals buy insurance and insurers cover a list of "essential health benefits". The Tax Cuts and Jobs Act of 2017 zeroed out the federal tax penalty for violating the individual mandate, starting in 2019. (In order to pass the Senate under reconciliation rules with only 50 votes, the requirement itself is still in effect.) To help households between 100–400% of the Federal Poverty Line afford these compulsory policies, the law provides insurance premium subsidies. Other individual market changes include health marketplaces and risk adjustment programs.
Since being signed into law in 2010, the PPACA has faced strong political opposition, calls for repeal (from Republicans) and numerous legal challenges; its enactment is considered to be a catalyst for the Tea Party movement. In National Federation of Independent Business v. Sebelius, the Supreme Court ruled that states could choose not to participate in the ACA's Medicaid expansion, although it upheld the law as a whole. The federal health exchange, HealthCare.gov, faced major technical problems at the beginning of its rollout in 2013. In 2017, a unified Republican government attempted but failed to pass several different partial repeals of the ACA. The law spent several years opposed by a slim plurality of Americans polled, although its provisions were generally more popular than the law as a whole, and the law gained majority support by 2017.