You are not correct about coinsurance when using in-network hospital and providers. There is a contracted rate with the insurer and your out of pocket is usuall

You are not correct about coinsurance when using in-network hospital and providers. There is a contracted rate with the insurer and your out of pocket is usually 20%+ of that up to your out of pocket limits. The hospital does have arbitrary made up prices called a chargemaster which is just essentially numbers pulled out of a hat but when you are using an in-network provider there is a fixed rate for every covered code.