My doctors are all in the same building attached to my hospital. Although they're all different practices/companies, they all know each other very well. And, once I've signed the forms allowing them to, they communicate directly with each other. This has been a huge help to me. Not only does it save me appointments and copays to essentially transfer information back and forth, but they know each other well enough that they are able to discuss and figure out things together rather than battling with each other. My favorite example was when I met my PM once and we were talking, a symptom came up that I had never mentioned because in my mind it was small compared to everything else. Well my PM felt it changed things, so he went and called my Ortho on the phone, who answered right away because they know each other, and within five minutes they decided together on a different course of treatment.
I'm going to give one more, because I also feel it's what makes my doctors individually great and not just a great team. All my current doctors, but especially my PM make it clear to me that they really care about me not just as a customer, but as a person and in many ways as a friend. When I talk they never cut me short, they listen and they ask questions that show they really care. They really treat me as a friend that they have the ability to help. They are also very good at reading me and asking the questions I'd rather avoid. Rarely do they have to check my chart. The same way I remember what's going on in the lives of my friends, they remember me. This is what makes me able to trust them so well. And trust is so important. I could give so many examples, but then this post would be several pages long, so I'll leave it at that.
Great doctors really make the difference!