From a Social Security press release:
I hope this doesn't cause problems. Programs used to compute payroll have to have the correct FICA wage cap. There will be problems if those programs aren't corrected.
In October of each year, the Social Security Administration announces adjustments that take effect the following January that are based on the increase in average wages. Based on the wage data Social Security had at the time of the October 13, 2017, announcement, the maximum amount of earnings subject to the Social Security tax (taxable maximum) was to increase to $128,700 in 2018, from $127,200 in 2017. The new amount for 2018, based on updated wage data reported to Social Security, is $128,400. ...This is odd. Why wouldn't Social Security have had the correct data as of October 13, 2017? It looks like someone goofed but the goof may have happened outside the Social Security Administration. In fact, it sounds like they're saying that someone else, perhaps Treasury, gave them incorrect information.
I hope this doesn't cause problems. Programs used to compute payroll have to have the correct FICA wage cap. There will be problems if those programs aren't corrected.