[kevingadd]

Insurance companies can and will reject treatments recommended by a doctor on a regular basis. It's not hard to find examples of this. You can insist that The Rules say TB is exempt from this but laws aren't real unless the people responsible for enforcing the rules believe in them. Do you think some faceless health insurance administrator - whose name you don't even know - is going to go to prison for rejecting your TB treatment? Have fun with months of appeals and maybe having to retain a lawyer to get your treatment.

I've personally dealt with this post-ACA (though not for TB).