According to Social Security Administration and their website, there is no mention of any schedule changes related to the 2018 shutdown as of 12/26/2018.
What You Need To Know
Since the Treasury Department is one of the agencies not covered by funding during this shutdown, the IRS has furloughed majority of its employees. December and January are hot times for the IRS, but thanks to special implementation funding included in the Tax Cuts and Jobs Act, the IRS will be able to keep critical staff working to deploy the 2019 W-2 filing season.
However, many of these staff are IT workers who keep the systems operating behind the scenes, so day-to-day IRS services that your payroll department and your employees rely on such as telephone support and taxpayer appointments at assistance centers will be adversely affected by the shutdown. Think IRS, minus 90% of its staff at tax filing and ACA time.
Taxpayer levies are another area of concern for payroll departments. When a levy is enforced on a taxpayer’s bank account, the taxpayer is given 21 days to make alternative arrangements and obtain a release of his/her levy. Unfortunately, if there are no IRS employees with whom to make such arrangements, taxpayers may not have this option available.
Pack your patience if you need to contact the IRS during the shutdown!