My Dad is in Chronic Condition

Good day to all! I want to know about this chronic care management services. What is it all about? I just heard it from a friend whose parents are into it. I think, its doing good for them since they are having a difficult time if patient with chronic condition will spent their time just to see their doctors. Perhaps, its very convenient for the physician and the patient who are seniors already like my dad. I just want to know, how do we know that the patient is eligible for it? Do we have to signed an agreement? We want to know too if most doctors are participating already in this type of service or rather a program?