The ACA has significantly expanded health insurance coverage, reducing the percentage uninsured from around 16% in 2010 to 9% in 2015.[1] ACA covered approximately 24 million people in 2016 via the exchanges and Medicaid expansion.
Healthcare costs in the employer market have continued to grow at historically low levels, a trend which began before the ACA and continued thereafter. In other words, there is no adverse impact (and perhaps some positive impact) in the employer market.[2]
By raising taxes on higher income taxpayers and transferring benefits to lower incomes, the ACA and expiration of the Bush tax cuts for the top 1% shifted the distribution of after-tax income in a way that is expected to reduce income inequality in 2017. The 2017 Economic Report of the President states: "Together, changes in tax policy and the ACA coverage provisions will increase the share of after-tax income received by the bottom quintile of households in 2017 by 0.6 percentage point, or 18 percent—equivalent to more than a decade of average income gains—and the share received by the second quintile by 0.5 percentage point, or 6 percent. At the same time, they will reduce the share received by the top 1 percent by 1.2 percentage points, or 7 percent. These changes will increase average tax rates for the top 0.1 percent of families, a group projected to have average pre-tax incomes over $8 million, by nearly 7 percentage points."[2]
Multiple CBO studies have indicated ACA is a deficit reducer, with tax increases on roughly the top 5% of income earners and reductions in future Medicare costs offsetting subsidy costs. This particular graph shows the 2015 CBO estimate for a sizable increase in the deficit if the ACA were to be repealed ranging from $137-$353 billion over 10 years. [3]