If your employer paid the premiums or if you paid the premiums with pre-tax dollars, then the income you get on disability is taxable. However, if you paid the premiums with after-tax dollars, then your disability income payments are free from federal taxes.
Your social security disability benefits may be taxable if the total of (1) one-half of your benefits, plus (2) all of your other income, including tax-exempt interest, is greater than the base amount for your filing status.
The base amount for your filing status is:
$25,000 if you're single, head of household, or qualifying surviving spouse,
$25,000 if you're married filing separately and lived apart from your spouse for the entire year,
$32,000 if you're married filing jointly,
$0 if you're married filing separately and lived with your spouse at any time during the tax year.