Hi and welcome, Nancy in Clearwater, Florida ~
I'm not an authority on medical insurance but I believe that once your doctor perform s the surgery (or radiation) the aftercare is included in his fee, but I would get this clear with the doctor or someone on his billing staff. In my experience, Blue Cross covered all the costs of my AN surgery once I had met my 'out-of-pocket' deductible ($2,500.) There were no follow-up, aftercare costs.
It's unfortunate, but in light of the fact that your insurance coverage will be terminated on September 30th, 12 days from today, making a treatment decision and having the surgery, if that is your choice, is imperative. I believe your AN is small enough to be irradiated, but that is for a physician to decide. However, as urgent as your decision is, please try not to jump into anything without some real thought as to what you want and what doctor you're comfortable with and feel confident about, because choosing a doctor is crucial. Please let us know your decision. Thanks.
Jim