Step 1: Setup employee deduction 

1. Select PR, Utilities, Maintain Deductions.
2. Click New.
3. Define a deduction for the employee's portion or contribution.
   Method (of calculation): Usually 'Percentage of Gross'
   Category: 'Individual' (to allow each employee to specify a different percentage)
   Credit account: Specify the liability account defined for the deduction
   Limit, if any: Enter the dollar amount for the limit
   Specify the annual limit, if any, you can withhold by law 
4. Taxable boxes. Check with your tax advisor or plan administrator for taxable status
5. Tax category: 'None'.
6. Select the 'W-2...' button.
   Retirement Plan: Checked.
   Box number: Normally Box 12, but check with a tax advisor.
   Box ID: Check with a tax advisor.

Step 2: Setup employer's match

1. Select PR, Utilities, Maintain Deductions.
2. Select New.
3. Define a deduction for the employer's match portion, if applicable.
   Method:(of calculation): Usually 'Percentage of Gross'
   Category: 'Company-Ind' (to specify a varying match depending on the employee contribution)
   Credit account: Specify the liability account defined for 401K deductions
   Debit account: Specify the expense account defined for the employer contribution
   Limit, if any: Specify the annual limit, if any, of the employer match
   Taxable boxes: Check with a tax advisor for the plan's specific tax requirements
   Tax category: 'None'

Step 3: Add both deductions to the employee 

1. Select PR, Employees, Maintain Employees.
2. Click the 'Deductions' button.
3. Add both deductions specifying the correct percentages or amounts.
4. Repeat for each employee.