If you are not in the University of California Retirement Plan (UCRP) you may have Safe Harbor. Employees with Safe Harbor do not pay into Social Security. Instead, they contribute to the Defined Contribution Plan (DCP) pre-tax account. Contribution is mandatory.
Generally, student employees, part-time employees, seasonal employees and temporary employees contribute to the DCP.
The default investment for the DCP plan is the UC Savings Plan. There are a variety of different investments available through Fidelity Investment Services. Click here for more information for Safe Harbor Participants.