Hello, I work for an insurance company(BCBS IL actually) and see these quite often. I would recommend calling you insurance company and asking exactly what they're looking for. Also, if you go to the Provider section of their website you can probably find the Medical Policy that they're referencing and you can provide that to your surgeon to let them know in detail what is required. If they still deny your surgery after they get the info requested then ask how to appeal the decision. The reason these surgeries get denied so often is because the insurance company has a strict policy that they're adhering to but if it's truly medically necessary for your health and if you stick with it, you can most likely get that approval. The letter you posted doesn't say that you DIDN'T meet any requirements, just that something was missing so I would say your chances are good. As for the two reasons listed, it looks like the first part that says "Not a medical necessity' is just the standard verbage meaning that all requirements not met. It is the second paragraph that gives you the info you need on what was missing. Good luck to you and if you need any help with insurance lingo, let me know and I'll help you decipher things.
Sarah