You must report as income any amount you receive for your disability through an accident or health insurance plan paid for by your employer: If both you and your employer have paid the premiums for the plan, only the amount you receive for your disability that's due to your employer's payments is reported as income.
https://www.irs.gov/faqs/interest-dividends-other-types-of-income/life-insurance-disability-insurance-proceeds/life-insurance-disability-insurance-proceeds-1#: