Thanks for joining in this thread, @Beach05.

Currently, you can only choose one deduction of the same type in QuickBooks Online (QBO). However, you can set up a regular 401(k) retirement plan first. When it reaches the annual maximum amount of $23,000, you can delete the regular 401(k) and create the 401(k) Catch-up. 

Here's how:

1. Go to Payroll and select Employees.
2. Click the employee's name and select Edit in the Deductions & Contributions section.
3. Click + Add deduction/contribution.
4. In the Deduction/contribution dropdown arrow, select the + Add deduction/contribution.
5. Choose Retirement plans in the Deduction/contribution type.
6. On the Type dropdown, choose 401 (k) Catch-up.
7. Fill in other necessary fields, then Save.

To delete the regular 401(k) plan, click the trash bin icon and select Delete to confirm. You can then follow the same procedure mentioned above to set up the 401(k) Catch-up retirement plan.

Furthermore, you can run payroll reports in QBO to view your payroll totals, including your employees' deductions and contributions.

Let me know if you need further assistance setting up 401(k) retirement plans for your employees. I am always available in the Community to help. Take care.