California — highest state income tax in the US
California has the highest state income tax rates in the United States with a top marginal rate of 13.3% on income over $1 million. For most workers, the effective rate is much lower — a worker earning $75,000 pays approximately 9.3% on their top dollars but their overall effective rate is around 5.9% after the $5,202 standard deduction and lower brackets on the first portion of income.
A worker earning $75,000/year in California takes home approximately $51,800 per year — about $8,200 less than an equivalent worker in Florida or Texas where there is zero state income tax. That difference compounds to over $82,000 over 10 years.
California SDI — State Disability Insurance
California also charges SDI (State Disability Insurance) at 1.1% on all wages with no wage cap (2026). This is an additional payroll deduction on top of state income tax that most other states do not have. SDI funds California's short-term disability insurance and Paid Family Leave programs.
For a $75,000 salary, SDI costs $825/year ($31.73 per biweekly paycheck). If you become disabled or need to take paid family leave, you can receive 60–70% of your wages up to a maximum weekly benefit. SDI is deductible on your federal tax return as a state tax paid.
California standard deduction — much lower than federal
California has its own standard deduction of only $5,202 for single filers (2026) — dramatically lower than the federal standard deduction of $14,600. This means your California taxable income is much higher than your federal taxable income, resulting in more state tax owed.
For example: $75,000 gross - $5,202 CA standard deduction = $69,798 CA taxable income. Compare this to federal: $75,000 - $14,600 = $60,400 federal taxable income. The low CA standard deduction is a major reason California's effective tax burden is so high even for middle-income workers.