I guess that’s one benefit of the US’s terrible health system? There isn’t a single “system” so even if one doctor diagnoses you with something, a different doctor in a different office won’t have any idea about it unless you volunteer the information.

Wait the US doesn't have a centralized/shared medical records service? I never realized that! In France, I suppose like in the UK, we have our "Carte Vitale" ("Life/Vital Card"), which is scanned each visit to a doctor, hospital, pharmacy, etc, each updating your personal database nationally.

It also serves as a link to your insurance provider in each location, so reimbursements are automatic.

Nope, doctors can't see you medical information unless you give it to them.

There must be some sort of system that shares info some of the time. I signed up for a new doctor (haven't even visited yet) across the country from my old one, and the website of my new doctor's medical center already knows all my historical vaccine dates. I didn't give any of that information over, just my name, birthday, and SSN.

Usually by fax.

Or by handing them a CD

Just FYI, this is increasingly less true in many respects...although the opposite problem also occurs, where there is so much noise that the important pieces for any given visit do not surface for the doc.