Nephrology Billing Service [ http://www.hiiweb.com/ ]
HII is a recognized industry leader in clinical and financial systems and managed services in CKD, ESRD, and CDM.

Primary Source Verification [ http://www.physiciansbillinggroup.com/about/ ]
Physicians Billing Group is a full service medical practice consultancy specializing in primary source verification, medical credentialing, and hospital billing.