The Obama administration was able to push the Affordable Care Act — Obamacare — through Congress in part because the Congressional Budget Office said it would modestly reduce future federal budget deficits. The claim of deficit reduction rests on a shaky foundation. It depends entirely on the uninterrupted implementation of four carefully constructed “indexing” provisions. These provisions, which make annual adjustments to key spending and tax parameters of the law (or specify that such adjustments will not be made), were written with the clear intention of making the ACA look better financially as time passed. Our new study, published by the Mercatus Center at George Mason University, shows that these budgetary manipulations are no more likely to survive mounting political pressure than did income-tax “bracket creep” in the 1970s or across-the-board cuts in Medicare physician fees over the past 15 years.