IRS tax deductibility of SDI, State Disability Insurance, and VDI, Voluntary Disability Insurance?

You can deduct certain mandatory contributions, as noted below. The fact that they are mandatory (by the state) is probably what makes them deductible as a tax. Contributions to state benefit funds. As an employee, you can deduct mandatory contributions to state benefit funds withheld from your wages that provide protection against loss of wages. Mandatory payments made to the following state benefit funds are deductible as state income taxes on Schedule A (Form 1040), line 5. California Nonoccupational Disability Benefit Fund. New Jersey Nonoccupational Disability Benefit Fund. New Jersey Unemployment Compensation Fund. New York Nonoccupational Disability Benefit Fund. Rhode Island Temporary Disability Benefit Fund. Washington State Supplemental Worker's Compensation Fund. West Virginia Unemployment Compensation Fund. Employee contributions to private or voluntary disability plans are not deductible.

I am presuming you are a Californian like me. SDI is deductable as tax on federal returns because it is a collected tax. California does not allow this particular deduction. VDI is not a tax.