The new tax tables have been released for 2018 withholding. If you have not already put them to use you have until Feb 15th.
IRS Notice 1036 goes over not only the withholding tables but also goes over 2018 Medicare and Social security rates. Make sure you are using the correct rates and limits for your payroll tax withholdings and filings.
Please contact me if you want me to help you with your bookkeeping needs.
I have attached a link to the IRS notice listed above.