health insurance through employer, right to reimbursement for not using company's health plan under IL employment laws

Sorry, but no. Some employers offer a small reimbursement to employees when they forego using their health plan benefit, but this is optional. Personally, I have never seen an employer who reimbursed the employee in full for this. An employer is not required by law, typically, to provide any health plan benefit at all. If they were that would be a form of universal health coverage. Thus your health plan benefit is just one of potentially several employee benefits offered to you. If you think about it, there are probably other employee benefits offered as well that you will never use. Perhaps your employer will look favorably on you as a team player, but that is about the most benefit to you.

Barbara Gallios, Attorney at Law
Making sure insurance companies keep their promises.