Form 4029

On Form 4029, the Preparation of Form W-2 section of the Instructions to Employers tells you to specify Form 4029 in the box marked "Other:" Do not make any entries in the boxes for Social Security wages, Medicare wages, Social Security tax withheld, or Medicare tax withheld.
Note: The employer must be identified as a Form 4029 Employer by selecting the Form 4029 Employer check box located at Payroll Administrator > Regulatory Reporting > Year End Reporting > Employee Configurable Fields. After selecting the check box for the applicable legal entity, W-2 Reporting checks the employee configurable fields set up for printing Form 4029.