Under BlueCross BlueSheild Carefirst program, can Breast Reductions not be deemed medically necessary until post op evaluation?

It sounds like your carrier used to do preauthorizations for breast reduction, but have stopped doing so. Unfortunately, this is their call. My hunch is that the carrier expects fewer women will go through with the procedure were there uncertainty about coverage. I suspect that had they previously decided that the procedure were medically necessary by pre-authorizing the procedure before, they would be hard pressed to say later that it was not.All the best. 

Unfortunately, it can be frustrating when dealing with health insurance companies; they are in the position to be able to “change the rules” when it comes to coverage for breast reduction surgery. You may want to double check the information received with another official from the insurance company. When I see patients in consultation for breast reduction surgery, I remind them that this operation is one of the most patient pleasing operations performed;  it is worth being patient and persistent when dealing with health insurance companies. Best wishes.