Hi there, rhogarth.
You will need to create payroll liability adjustment to correct the taxes for the 4th Quarter. Here's how:
- Go to the Payroll Center and click Adjust Payroll Liabilities under the Other Activities section.
- You can use the last day of the year (12/31/2018) for both Dates and Effective Date.
- Select Employee in the Adjustment is for section, then look for the name of the employee.
- Select Social Security and Medicare taxes (both employee and company) in the Item Name column.
- Enter the amounts in the Amount and Wage Base columns.
- Click OK.
You might also want to inform the employee about the adjustment so you can deduct the taxes that should have been withheld last year. I've attached screenshots below for more details.
Let me know if you need anything else.