In the State of Illinois an injured worker cannot sue his employer or a co-employee for an injury that is covered under the Workers Compensation Act. Monetary recover is provided without consideration of who was at fault for causing the accident and injury. On the other hand the worker must repay a portion of his monetary benefits to the employers" insurance company if he recovers a settlement in a personal injury lawsuit filed against an independent third party that caused the accident and injury.
The Illinois Worker's Compensation Act provides that if you are injured in the course of work, and it is the fault of someone else, the employer (its insurance company) is entitled to a "lien" against any settlement or recovery obtained against a responsible third party. The idea behind the law is to avoid a double recovery to the injured party and to further force him to share his recovery from the ultimate responsible party with those that have paid his workers compensation benefits. If you do not have nor pursue a personal injury case against a third party, then your benefits do not get paid back.
Basically, this means that that if you were working and were injured due to someone else's negligence, Worker's Compensation's Insurance Company will be reimbursed for the wage and medical benefits paid to you if you get a personal injury settlement. A good example of such a situation is as follows:
You work for a trucking company and while making a delivery another vehicle driven by a third party strikes you causing you physical injuries.
When your attorney attempts to settle your case against the third parties insurance company the lien can become a serious obstacle. Perhaps the third party claims that you were partially at fault for causing the accident and offers a sum of money smaller than the amount of the workers compensation lien? In that scenario all recovered money would be paid back to satisfy the lien, leaving you with nothing. As a practical matter what often occurs is for the responsible third party to file within the third party lawsuit, what is known as a Contribution Counterclaim against your employer (something you are not permitted to do directly) claiming that its failure to properly train or supervise you caused the accident. What this tactic does is to try and force the employers' insurance company to waive all or a portion of its workers compensation lien in return for dismissal from the lawsuit.
As you can see the resolution of workers compensation and third party personal injury lawsuits are complicated, requiring the skills of a highly experienced attorney knowledgeable in the intricacies of both areas of the law. When involved in a worker compensation or accident it is extremely important to retain the services of an attorney that concentrates his practice in this area of the law.