This brief reviews the evidence on how key ACA provisions have affected the growth of health care costs. Coverage expansions produced a predictable jump in health care spending, amidst a slowdown that began a decade ago. Although we have not returned to the double-digit increases of the past, the authors find little evidence that ACA cost containment provisions produced changes necessary to “bend the cost curve.” Cost control will likely play a prominent role in the next round of health reform and will be critical to sustaining coverage. gains in the long term.