8511 / Why are many tax provisions indexed for inflation each year?

Many tax provisions are indexed annually for inflation so that increases in a taxpayer’s income that result solely from inflation do not push them into a higher tax bracket or over thresholds that would reduce or eliminate certain tax benefits.

Example: Asher, who is a single taxpayer, earns $83,500 as the manager of a computer superstore. Assume at that income level, Asher is at the very end of the 24 percent tax bracket. At the end of the year, he receives a cost of living adjustment (another term for an adjustment for inflation) that increases his salary to $84,500. If tax brackets were not indexed for inflation, Asher’s cost of living raise of $1,000 would be taxed at 32 percent. Yet, based on inflation, $84,500 of today’s dollars is the equivalent of $83,500 of yesterday’s dollars. Thus, without indexing, Asher would experience a tax hike. However, by adjusting the tax brackets by inflation, Asher’s tax liability essentially remains

The 2017 tax reform legislation provides that items that are adjusted annually for inflation will be adjusted based on the Chained Consumer Price Index for All Urban Consumers (C-CPI-U), as published by the Department of Labor, for tax years beginning after December 31, 2017 (this change was permanent).²