The Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI-W) increased 3.1 percent over the last 12 months to an index level of 246.196 (1982-84=100). For the month, the index increased 0.2 percent prior to seasonal adjustment.
The CPI-W for:
January 2018 241.919,
Their average is significantly higher than the 2017 benchmark average. That average is 239.668
For the last three months the average is 245.504.
What matters for a COLA are the months of Jul, Aug and Sep That average in 2018 must reach at least 246.858 for there to be a 3% COLA.