Obama signs Affordable Care Act, creating Medicaid expansion to 138% of federal poverty level

President Barack Obama signs the Affordable Care Act on March 23, 2010, including a provision expanding Medicaid eligibility to all adults with incomes up to 138 percent of the federal poverty level. The expansion is initially mandatory for all states, with the federal government covering 100 percent of costs for the first three years and at least 90 percent thereafter. The law is designed to extend coverage to an estimated 15 million low-income adults who do not qualify for existing Medicaid. The Supreme Court rules in 2012 that the mandatory expansion is unconstitutional as applied but allows states to choose whether to expand, creating a patchwork coverage system where red-state holdouts leave millions of low-income adults in a coverage gap.