[dba-SQLServer] Question about American medical systems

Presumably somebody here has experience in developing software for American medical applications. I don't need to know everything about it; I just have one precise question at this moment, although I reserve the right to ask more. 

In Canada there is a notion called a Consent. I will depict it with an illustration:

For x years, my family physician was Joe. Then I moved and got a new physician called Jill. Jill does not have the right to view my medical history without my signing a Consent. Now, further assume that I am female, and that I am pregnant, and that I now acquire the services of an obstetrician in addition to my family physician. (The point here is that multiple Consents can co-exist.)

Is this at all similar to the situation in the USA? And while I'm at it, comments are also invited from developers in other nations.

TIA,
Arthur