Some private insurance companies have a clause in their policies that continue the COB period after transplant. I have never seen this challenged, and I successfully fought my insurance company on that one. (I was transplanted after 22 months on dialysis, and a year after my transplant they tried to not pay for anything ESRD related - I had fun fighting that one).
Here is more that you will ever want to know about Medicare and Coordination of Benefits (not just ESRD)....
What is the Common Working File (CWF) that I wrote about?
The CWF is the system that CMS uses to verify a resident’s entitlement to and correct use of Medicare benefits. When a person signs up for Medicare, the government establishes a record of him or her in the CWF. The CWF therefore contains each resident’s national Medicare record.
Here is what CMS has on Coordination of Benefits:
http://www.cms.gov/BeneficiaryAdvocateServices/01_overview.asp