According to the Bureau of Labor Statistics, the Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI-W) increased 1.6 percent over the last 12 months to an index level of 226.600 (1982-84=100). For the month (of May) the index decreased 0.2 percent prior to seasonal adjustment.
This is the inflation indicator that determines the Social Security cost of living allowance.
For a more complete explanation read this post.
Categories: Social Security