So then you will use the HIC # (their Medicare #), bill Region C DME MAC, if your software only shows Medicare or commercial just put Medicare on it. But the address should read Region C DMERC and their address along with the payer ID for the DME MAC. Don't send it to regular Medicare for your state.
https://www.cgsmedicare.com/jc/index.html#
https://www.cgsmedicare.com/jc/index.html#