The VA sort-of does this, at least when I worked for them. The issue they had when I was there was depending on where you went, you may or may not have access to the record, because the VA didn't use a central system, it used many systems across the country, each with their own records(basically their own mainframe). We once added a hospital to our system, and had to have dual workstations because the systems couldn't be easily merged, and they had to look up patients in both systems.
Also, with Veterans Choice, I don't know how much there was an effort to bring this data back. Same thing with the DoD, for a while there was an agreement to send medical records for active duty to the VA, but then that got pulled for a time.
I believe there was a huge undertaking to consolidate these to fewer systems in the last few years, but Vista[0] (the VA's EMR) is pretty scary. I wouldn't wish it on anyone.
The VA has something called BlueButton that looks really cool (https://www.va.gov/bluebutton/) and I think should be standard practice across all EMS systems (one click export of all a patient's data to a single text file).
The file format itself seems like a bit tough to parse, but the concept I love.
Blue Button technically is an industry-wide standard though its origins were indeed in the government. I've seen it supported in a couple of the private healthcare systems I've used (though I haven't ever used the resulting data download unfortunately!).
Also, with Veterans Choice, I don't know how much there was an effort to bring this data back. Same thing with the DoD, for a while there was an agreement to send medical records for active duty to the VA, but then that got pulled for a time.
I believe there was a huge undertaking to consolidate these to fewer systems in the last few years, but Vista[0] (the VA's EMR) is pretty scary. I wouldn't wish it on anyone.
https://en.wikipedia.org/wiki/VistA