No, you do not have to choose between filing an Illinois worker’s compensation case and a third-party liability suit. You can file both, provided that someone else is to blame for your work injury besides yourself, your employer, or a co-worker.
However, the relationship between the third party case and the worker’s compensation case is very complex, so we strongly recommend that if you are going to file a third party liability suit that you hire an experienced Chicago personal injury lawyer to assist you.