In my paycheck stud they take money away for FiCA and SDI, what are those? And do I get a refund at tax time?

FICA:
If you're a wage or salaried employee, your employer picks up half of this tax. burden.

the Federal Insurance Contributions Act (FICA), 12.4 percent of your earned income up to an annual limit must be paid into Social Security, and an additional 2.9 percent must be paid into Medicare.

SDI:
California State Disability Insurance (SDI) is a partial wage-replacement insurance plan for California workers. The SDI program is State-mandated, and funded through employee payroll deductions. SDI provides affordable, short-term benefits to eligible workers who suffer a loss of wages when they are unable to work due to a NON WORK-RELATED illness or injury, or a medically disabling condition from pregnancy or childbirth.

The majority of California employees, approximately 12 million workers, are covered by the SDI program. Some employees are exempt from SDI; for example, railroad employees, some employees of non-profit agencies, employees who claim religious exemptions, and most government employees.

Four other states and one Commonwealth offer a disability insurance program. They are Rhode Island, New Jersey, New York and Hawaii, and the Commonwealth of Puerto Rico. Each state operates its program independently.

BENEFITS OF CALIFORNIA SDI COVERAGE
SDI coverage "travels" with the worker. Coverage is not dependent on staying with a specific employer.
SDI coverage is mandatory for most California workers.
SDI is non-exclusionary. An eligible worker's coverage cannot be canceled or denied because of health risk factors, pre-existing medical conditions, or hazardous employment.
SDI may pay up to 52 weeks of benefits with a waiting period of only seven days.
Payroll deductions for all covered workers are based on the same low contribution rate.
SDI PLANS

The Disabiliity Insurance Branch of the California Employment Development Department (EDD) administers three disability insurance plans:
State Plan. The majority of employees in California are covered by this plan, and most of the information provided on the Disability Insurance portion of this site pertains to the State Plan.

Voluntary Plan. This is a private plan, approved by the Director of EDD, which may be substituted for the State Plan. Employers and employee groups may establish Voluntary Plans if the majority of employees and the employer agree to do so. If you are covered by a Voluntary Plan, the provisions of this site may not apply to you. Obtain information about your coverage and file a voluntary plan claim through your employer.

Elective Coverage. Employers and self-employed persons, including general partners, may elect coverage. However, the method of computing benefits for elective coverage participants is not the same as for employees whose coverage by the State Plan is mandated. The cost of participating, which is set annually, can be obtained by contacting your local EDD Employment Tax Office.

Individuals in family employment not subject to the California Unemployment Insurance Code may also elect coverage at the same rate as employees covered by the State Plan and with the same benefits as the State Plan.

Elective Coverage claims are filed in the same manner as State Plan claims; however, there are some differences in eligibility requirements from those listed on this site. For additional information or to apply for coverage, contact EDD Disability Insurance Customer Service at 1-800-480-3287 or EDD Taxpayer Assistance Center at 1-888-745-3886.