Workers’ compensation insurance is a state-mandated program that exchanges compensation for job-related injuries and illnesses for relinquishing the right to sue for damages. While each state has its own comp laws, none can violate federal employment laws or provisions in the Americans with Disabilities Act. This means an employer may have the option to terminate you while you have an open workers’ comp claim, but can't fire you just because you filed a claim.
According to the National Conference of State Legislatures, in every state except Montana, employment in the U.S. is mainly at-will. This means both you and your employer have the right to terminate the relationship anytime and for any legal reason without prior notice. The burden lies on you to prove you were fired directly because of a workers’ comp claim. However, an employer who says or infers that your job will be secure creates an implied contract of employment that supersedes the at-will relationship. According to Judge Anthony P. Calisi, this may afford you an implied legal right not to be fired during recovery or after returning to work.
ADA protections can also prohibit the company from firing you based on a short-term or permanent disability. When it comes to ADA violations, the burden of proof is on your employer. The employer can make a valid case for the termination, such as it had no choice due to financial circumstances. But the burden of proof of that is so high that most will hire a temporary employee and wait for you to return.
Beth Laurence, an attorney and legal editor for Nolo.com, notes that your employer must keep you as an employee until you fully recover or reach a point where you're unlikely to improve despite ongoing treatment. However, an employer can terminate you if you reach maximum medical improvement and have permanent work restrictions the employer cannot reasonably accommodate. For example, if you're a warehouse worker but can no longer lift more than 10 pounds, your employer can offer you an alternate position or terminate you.
Employees covered by an employment contract usually have more protections than those employed at-will, but there are exceptions. Laurence wrote that many employment contracts include a clause that gives an employer the right to terminate an employee who is unable to work for a specific time. If your recovery period exceeds the stated time, Laurence says this is a legal reason for termination.