Like 529 plans sponsored by other states, California's state-sponsored 529 plan can offer tax-advantaged growth as well as a way to potentially shrink your taxable estate. While contributions to California's plan are not deductible at the state or federal level, all investment growth is free from state and federal taxes, and the earnings portion of withdrawals for qualified education expenses are income tax free. (Note that contributions to some states' plans can be state tax-deductible for residents of those states).