Dependency and Indemnity Compensation, the monthly VA payment to survivors of a service member who died in the line of duty or a veteran whose death resulted from a service-connected injury or disease, is tax free and is not taxed by Illinois.
There is nothing to apply for. Leave your Dependency and Indemnity Compensation payments out of the income you report on your Illinois return.
Your VA award letter showing the Dependency and Indemnity Compensation payments.