None, would be the answer in almost any circumstance where orthodontic treatment is recommend. This is an area of confusion for many consumers but standardly orthodontia is viewed as a dental and not a medical procedure. Therefore, orthodontia might be covered under a dental insurance plan (if it has the orthodontia coverage benefit level) but not under an individual or group major medical policy.
The only circumstances where a health insurance plan might conceivably cover orthodontic procedures would be in the relatively rare situations when the criteria for medical necessity would be met. Some examples might be in cases of facial deformities, speech impediments and severe jaw pain. Even then it is likely to be no small task to get approval from a health insurance company and you and your doctor(s) will have to be prepared to make a very strong case that this is the only viable way to deal with a medical (not dental) issue.
The only circumstances where a health insurance plan might conceivably cover orthodontic procedures would be in the relatively rare situations when the criteria for medical necessity would be met. Some examples might be in cases of facial deformities, speech impediments and severe jaw pain. Even then it is likely to be no small task to get approval from a health insurance company and you and your doctor(s) will have to be prepared to make a very strong case that this is the only viable way to deal with a medical (not dental) issue.