I went to my first appointment with a new primary care doctor. He is with a brand new healthcare system to the Albuquerque area. The dr explained to me it was established in the late 1990s by about 4 ER docs who had seen too many patients for things their primary care should have been dealing with but hadn't until the patient felt they had to go to the ER for help (my partner was definitely one of those!) So, with this system your primary care is precisely that: your PRIMARY care. He or she knows EVERYTHING about your health! And whatever h/she can't treat or test you for there at the clinic, they will refer you to a specialist who will be in close contact with your primary care so, again he/she will know EVERYTHING that's going on with you, can talk WITH you more indepth about all of it. And that is something I find most attractive about this whole concept--I become fully engaged in my healthcare rather than just being told what to do and when to schedule the follow up!
So it is going back in time in a way. Back to the days when you didn't have a "primary care" but a "famly" doctor or general practitioner and a specialist was rare, not your predominate line up of Dr's. When it was easy to call your Dr, easy to make an appointment to see yor dr--no waiting 3 months. What an idea!