A -2 percent cost-of-living adjustment (COLA) is effective beginning January 1, 2018. The average monthly Social Security benefit is $1,440 (vs $1,377 in 2017) for a retired worker. The average monthly benefit is $1,197(vs $1,173 in 2017) for a disabled worker.
Social security tax applies on wage and salary income up to $128,400. Workers receive a work credit for $1,320 of wage and salary income each quarter. They may earn four work credits each calendar year.
These changes are included in the 2018 fact sheet at: