Yes, you can get fired while on workers’ compensation. Most states, including D.C., VA, and MD, have provisions preventing employers from firing employees in response to protected behavior, such as filing a workers’ compensation claim (retaliation). However, this is rarely the issue.
As an at-will employee, your employer can legally fire you while your claim is open. Getting fired doesn’t end your workers’ comp case; the insurance company must continue benefits and cover medical treatment.