Tim -
you should contact the company that will be manufacturing your BAHA equipment and processor; i.e., Cochlear or Oticon.
Both these companies have separate insurance divisions that will contact your insurance company for you and explain why you need a BAHA, etc., Cochlear and Oticon employ people who do this for a living and they get results. There is no cost to you as far as I know. You just need to contact whichever company you/your doc intend to purchase your BAHA through.
Another thing to do is ask your insurance company if they pay for Cochlear Implants (CIs). CIs are for people who are bilaterally deaf - BAHAs are for people who are unilaterally deaf (SSD). If they cover CIs and don't cover BAHAs they are discriminating against you because you aren't bilaterally deaf. Make sure you point this out to them.
Finally, and very importantly, don't take no for an answer. It's a well known fact that insurance companies tend to turn down coverage for a BAHA the first time you inquire but, if you are persistant and keep asking, chances are you'll get positive results. Insurance companies aren't ever happy to part with their money and if they can give you a simple no that you don't "call" them on, it's money in their pocket. They're playing the odds that you'll just drop your request.
It took me 9 months to get my insurance company to agree to cover my BAHA implant and my processor - a process that should have taken 4-6 weeks. They kept losing my request; told me they weren't sure how I became SSD - which was laughable since they paid for my AN surgery and my operative report specifically said I lost the hearing in my left ear; asked me repeatedly what a BAHA even was; etc. In the end they paid for everything 100%.
Bottomline, don't give up. Fight this!
Good luck!
Jan