California's 6.6% figure is an optional payroll-withholding percentage in a specific payment context, not a universal severance tax rate.
The controlling first-party source for employers is California EDD's 2026 Employer's Guide, DE 44. The guide distinguishes supplemental wages paid with regular wages from supplemental wages paid separately.
What the 2026 guide says
At a high level:
- Paid at the same time as regular wages: payroll generally combines the supplemental and regular wages and withholds on the combined payment.
- Paid separately: payroll may calculate withholding using the regular method or use an optional percentage method under the guide.
- Optional percentage for certain other supplemental wages: the guide lists 6.6% for California personal-income-tax withholding. Bonuses and stock-option payments have a separately listed percentage and should not be assumed to follow the same figure.
The payment's classification and the employer's actual payroll method therefore matter. “California severance is always withheld at 6.6%” is too categorical.
Withholding is not final California tax
The 6.6% percentage method determines an amount withheld from a qualifying payment. It does not determine the employee's final California income-tax liability.
Final liability is calculated from the full tax-year facts, including total taxable income, filing status, deductions, credits, residence, work location, and California sourcing. The withholding shown on the wage statement is credited when the return is filed; it may be more or less than the final amount attributable to the income.
Federal and FICA calculations are separate
Federal supplemental-wage withholding follows IRS Publication 15, not California DE 44. Depending on the payment and prior wage withholding, qualifying supplemental wages may use the optional 22% flat method or the aggregate method. The portion above $1 million of cumulative supplemental wages paid by the employer during the calendar year is subject to mandatory 37% withholding.
Social Security and Medicare withholding also require year-to-date wage inputs. The 2026 Social Security wage base is $184,500. Employer Additional Medicare withholding begins after wages paid by that employer exceed $200,000 during the calendar year. These are payroll rules, not a calculation of final federal liability.
Beyond withholding
See the package beyond the tax estimate.
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How to use the 6.6% figure responsibly
Before using it, ask payroll:
- Will the severance be paid separately from regular wages?
- How will the payment be classified in the payroll system?
- Will California personal-income-tax withholding use the regular method or the optional percentage method?
- Are California disability-insurance or other payroll deductions expected on this payment?
- Can payroll provide a written pay-stub estimate?
If payroll confirms 6.6%, enter 6.6 as the state assumption in the Severance Pay Tax Calculator. If payroll confirms another percentage, use that instead. If it will use a table or aggregate method without an equivalent percentage, do not turn the 6.6% option into a claimed result.
What changed on this page
The former version treated 6.6% as the required California rate and stacked it with assumed federal, FICA, and state-disability percentages to publish one take-home figure. That was not defensible across the payment methods the official guides permit. This version scopes the percentage to its supported method and leaves other deductions to their own verified inputs.
For the broader distinction between California withholding and final liability, see How Is Severance Taxed in California?. For the nationwide verification workflow, see Severance Tax Rate by State 2026.
Updated 22 August 2026 from California EDD Publication DE 44. Educational information only; confirm the employer's payroll method and consider a qualified tax professional for advice about final liability.