I have joked before that I should wear an undershirt that says “Healthcare accepted only by in network providers <insurance ID #>. If out of network, stay away and let me die”.

I'm curious, would this even be essentially "accepted" by any hospital in the US? Not just a tag, but if you were going in for a procedure, could you even say "I want to be sure I will not be treated by anyone not covered by my insurance plan"? Because basically all the forms you need to sign upon admittance essentially say "We can charge you whatever we want and you are responsible for paying it."

They would tell you that you need to talk to billing, and billing would tell you they can't provide pricing at all and they can only tell you after going through your insurance, or they would require a zillion digit billing code that only your doctors can provide, and your doctors are not going to waste their time giving you the list of a thousand codes for whatever operation you're doing, or at least not accurately.

In short there is no way. Either you accept treatment and you're billed what you're billed and you hope insurance only fucks you over a little bit, or you're denied any service short of immediate life saving.

Whenever I took my vehicles in for service at a dealership, they would always provide a form for me to sign to pre-authorize any work they deem necessary. I always leave those forms blank. Never had an issue.

Whenever I go to a new doctor or medical facility, they always ask for tons of personal information such as my social security number. I always leave most of that blank. Never had a problem.

I've never been asked to write a blank check for a medical operation like I have at a dealership, but perhaps we should just make such practices illegal?

That's interesting. My mechanic always provides an estimate, then I sign something authorizing up to that estimate and that requires them to separately approve any further funding.

I would probably refer to the ethics dilemmas around "do not resuscitate" tattoos as the closest analog that I've heard about.