Ask your employer for a copy of the claim form to report a work injury or illness to your employer. Many state workers compensation agencies have a standardized claim form as well. Follow the instructions on the form, complete the "employee" section" and sign and date it. Make sure you keep a copy for your records. The employer will fill out the "employer" section. You can submit the form to your employer in person or by mail, but if you use mail it is usually recommended to send it by certified mail (return receipt requested) so you have a record of the date it was mailed and received.