This may be a a old discussion.
I was receiving 90% coverage on my transmitter insets. Turns out that my coverage was supposed to be 100% because the insets are "Durable Medical Equipment."
Anthem is reimbursing me. They were very helpful in resolving the problem. Not the evil medical insurance providers they are made out to be.
It was clear my pump and Dexc were DMEs (durable medical equipment) but not so clear with insets and transmitter.
It might be worth checking into if you have a co pay for insets and transmitters.
Oddly I had not trouble with pump insets.