The cost of an MRI (starting at $400, going way up depending on what was MRI'ed)[2], xray (starting at $100)[3] and an overnight stay (around $2600 non-ICU [4]) would be at least $3100 alone if you had to pay everything out of pocket, not accounting for any additional costs (the unspecified "additional tests" you mentioned, for example, or things you haven't explicitly mentioned but may still used like an ambulance ride, etc).
Of course, this is recent prices, and the prices may have varied when you actually were in hospital, and it is my understanding that prices both for health care services and procedures, and health insurance can vary widely depending on the region and the providers involved in the US.
But my google-fu let's me conclude that you indeed extremely likely had a health insurance plan at "platinum" level, far better than what most of your fellow citizens in the US enjoy.
Somebody with a plan near the "median deductible" would have paid that median deductible of more than $1400 in full, or around 10x what you had to pay, somebody unlucky enough to be on a "bronze" plan might have had to pay the full amount (or at least around 7 grand), and there are about 31 million people in the US without health insurance[5] who would have had to pay in full.
(Please note that I, as somebody who never experienced the US health care system, can thus only provide an outside view based on what I heard from people I know and in the media, and googled)
[1] https://www.investopedia.com/how-much-does-health-insurance-...
[2] https://www.itnonline.com/content/mri-costs
[3] https://health.costhelper.com/x-rays.html
[4] https://www.debt.org/medical/hospital-surgery-costs/
[5] https://www.statista.com/statistics/200955/americans-without...
I'm curious about this one. I've been to the hospital one time in my adult life. Stayed overnight, got multiple tests including an Xray and an MRI. Got medication, etc.
Having heard the horror stories I was ready for a big bill.
It was like $140.
It was cheaper than a hotel room would have been.
I can't tell if I just have exceptionally good insurance or if people who make a big deal about the US healthcare system are leaving out critical details.