You don’t actually fill out a specific disability form to report your income. Instead, you just report the payments using the tax forms the insurance company or your employer sends you, usually a W-2 or a 1099-R.
The main thing to be aware of is that if your employer paid for the disability policy, the money is taxable and you'll report it as income on your Form 1040. If you paid for the policy yourself with your own after-tax money, the payments are not taxed.
See: Is disability income taxable? for more information.
