In essence, no; your employer is not allowed to lay you off due to the fact that you were on workers' compensation leave, you can respond with an illegal retaliation claim. On the other hand, if your employer would have let you go even if you were still on the job, you are not protected by your workers' compensation leave since it is unrelated.
You have a right to work leave under workers' compensation statutes in every state. No employer may terminate, harass, lay off, or otherwise harm an employee for exercising their right to workers' compensation. You can sue any employer who has made you the victim of unlawful retaliation.
At the same time, those on workers' compensation are not entitled to special treatment due to their condition and leave. Even if an employee has filed a workers' compensation claim, their employer may still fire them for poor performance. If the reason for termination was unrelated to a workers' compensation claim or leave, there is a good chance it will hold up if challenged.
What about contracted employees?
If you are a contracted employee, your rights are different from one hired at will. You are still not able to be fired as retaliation for a workers' compensation claim. Your contract should enumerate the reasons your employer can terminate your employment. Common stipulations in employment contracts is a provision that gives the employer the ability to fire employees if they are unable to work for a given period of time.
If you were recently terminated from your job and you believe it was retaliation for being on workers' compensation leave, you should get in touch with the state workers' compensation board.