Which resource(s) to represent cohort health management

We have a large set of patients that are enrolled in various programs based in some criteria. We are thinking of using Organization, Group and Healthcare Service to depict the source organization, the cohort and the type of service these patients are getting. We are not sure if we should use Encounter it a different resource to express the state of enrollment into these various programs.
Does anyone have some similar situation they are dealing with?

Program enrollment isn’t really an appropriate use of Encounter. On the other hand, we don’t currently have an ideal resource to capture that. EpisodeOfCare would be closer - because enrollment could have a lot of encounters and other activities associated with it, but it’s not ideal. I’d look at using EpisodeOfCare or Basic for now and raise a change request suggesting a new resource to represent program enrollment. (And if you want to take a stab at what it should look like, that would be appreciated too :>)

EpisodeOfCare would make sense here as it is about the association of the patient to an organization for a period of time for a purpose.
So the sound of what you are doing looks like this.
Often you would associate eligibility, assessments, funding and encounters to this too.