I had gone to an urgent care clinic with abdominal pain. They pressed on my abdomen to see where the pain was and told me to immediately go to the hospital down the street and there would be a CT scan order waiting. At the conclusion of the scan, I was told to go down the hall to the ER for emergency surgery.
At the ER check-in counter, they took my information. My insurance was a PPO for which the hospital was in-network. After 20 minutes on the phone, they told me that my employer (a 6K person public company, not a small company just figuring out benefits) hadn't paid their premium so they would not admit me. I knew the head of HR and called her directly. She said that premium payments are automated and there were no issues. To make sure, she called our contact at the insurance company, and they confirmed everything was good. I told all of this to the front desk staff, and they said there was nothing they could do. They said they would contact the insurance company again the next day and call me if anything had changed.
Looking back, I should have gone straight to another hospital. But I was delirious with pain and went home to rest because I was exhausted and freezing cold from sweating profusely. The next afternoon they called and said it had been cleared up and that I need to get there immediately as it was life threatening. I got to the ER, and they started a series of tests to determine if my appendix had burst (it hadn't!). A doctor came over to review the test results, saw that the CT scan was the previous day, and yelled at me for several minutes about how I risked my life by listening to the front desk staff. I asked if I should have forced my way back to find an empty bed and just jumped into it. He continued to yell at me until a nurse physically pulled him away. I finally had the surgery late that night (with another doctor that was not so agitated), and everything went well from there.
So, I initially left the hospital against medical advice, but at the insistence of non-medical staff. A different situation, but sometimes taking medical advice is not an easy option.