CareCentrix is a billing company used by certain insurance companies to send bills to their clients. According to what I have found out, they pay the company in full (such as for rental of oxygen in our case) then Carecentrix turns around and bills the customer. Can they then bill whatever they want to? I'm not sure yet.
However, if you (as the customer) calls Carecentrix and asks what the bill is for, (IF you can get someone to answer the phone. I have waited for over a half hour before I hung up finally). They refuse to tell you what the bill is for or even what company it is for so there is absolutely no way to know what the bill is for. If you do not pay it, they immediately send it to collections at a company called NCO Financial Systems, Inc.in Norcross, Georgia.
I am turning them in to the insurance fraud division in the state of Colorado, plus any other investigative agency I can find. I believe they are ripping customers off (especially the elderly who need oxygen supplies the most).
The bottom line is that they bill you for whatever, will not tell you what it is for, then send you to collections and ruin your credit rating if you do not pay them. What a scam!