MMI stands for Maximum Medical Improvement. It is a medical term used when a patient has reached the maximum capacity to heal and that whatever injury plagues on, will continue permanently.
In the personal injury context, the attorneys for both sides usually await for the treating physician to determine give a report that the patient has recovered as much as the patient ever will. Once MMI is reached, the value of the case can be better ascertained. This is why your attorney is recommending that you wait until MMI is reached before settling. Also, many times, depending on the severity of the injuries the defendant’s insurance carrier will want to see what the plaintiff’s condition is once the maximum medical improvement has been reached.