In October, the IRS announced that the IRS social security wage base for 2018 would be increasing to $128,700. On November 27, the IRS subsequently released an update advising that this rate will be lowered to $128,400, which is still an increase of $1,200 over the 2017 wage base.
The Federal Insurance Contributions Act (FICA) tax rate, which is the combined social security tax rate of 6.2% and the Medicare tax rate of 1.45%, will be 7.65% for 2018 up to the social security wage base. The maximum social security tax employees and employers will each pay in 2018 is $7,960.80. This is an increase of $74.40 from $7,886.40 in 2017.