This page states that care team resources should be created from the participant list of a claim. This is not what a care team is. A care team is "The CareTeam includes all the people, teams, and organizations who plan to participate in the coordination and delivery of care for a single patient or a group (such as a married couple in therapy or a support group)." 

Just because a group of people treated me one time does not make them a care team. As a patient, I may choose to never interact with any of these providers again. Assuming that they are on my care team is invalid.

Additionally, to make an instance of a care team for every claim submitted would be a significant amount of duplication. Take for instance if I have dialysis 3 times a week and the facility submits a claim for each visit. Does that mean I 156 care teams each existing for 1 day last year alone?

I can certainly understand that you might use information gleaned from claims as a starting point to have a conversation with the patient as to who will be the care team going forward. But to use CareTeam as a "this group of people were involved in your care on a given day", is not a care team. Leave that data on the claim where it belongs.

Corollary: You can derive a patients conditions from examining claims, but you wouldn't create a new "Kidney failure" condition resource every time a claim was filed. You'd use that information to compile a single condition resource that has as much accurate information possible. And if you only saw that diagnosis 1 time in the history of claims, you might have a conversation with the patient, "Do you really have Kidney failure or was that an incorrect filing?"