An internal appeal occurs entirely within the insurance company. Claims representatives gather medical records and may have them reviewed by physicians or other medical analysts. Claims personnel may call your physicians to ask them questions. Your physicians may receive forms with requests to fill them out.
You should assume that though the law imposes upon the insurance company the obligation to perform a fair and impartial review, they will not do so. Remember, the insurance company will be paying these benefits out of its own pocket, yet they are going to be making a decision on your claim. Furthermore, all the documents gathered by the insurance company will be the entire record in your case if you have to file an appeal of the decision to a court. You will not have the right to testify before a judge or jury if your benefits are covered by federal law. Furthermore, you will not be permitted to put additional records of any kind, including medical records, before the judge who will decide your case. Most galling of all, the decision of the insurance company is entitled to a presumption that it is correct.