I think it depends on your Insurance Co. I have Kaiser and it was over 40 BMI with out co-morbidity's or over 35 BMI and 3 co-morbidity's (????). Well, you have diabetes that is one, if you do not have any others such as high BP, high cholesterol, heart disease, depression, joint pain, etc... You may not qualify. But, remember depression and joint pain are subjective so if you say you have them you do...
If you are self pay I am not sure what the requirements are, but I know they are not as strict.
I hope this helps!