re: What in the hell is wrong with medical billing?

You definitely need to compare any bills you receive with the EOB from your insurance company to see what the insurance paid and what they didnt, then see what you're billing billed for and whether or not the insurance company deems it something you're responsible for.

What you will want to watch for is being charged for services from a medical provider that you're insurance company denied (improperly billed, prior authorization not obtained, etc).

I've also seen one doctor bill my wife under two different tax IDs for office visits in the hospital on the same day.

So yea, if you're still on paper communications save all paperwork from every day of service and compare each bill against your EOBs. Should you need a new EOB they can almost always be downloaded fro their website or portal or requested by calling the number on your ID card.

Lastly, if you have questions about whether you are responsible for something youre being billed from a medical provider, call your insurance company and ask. Do not be bullied into paying a bill by the threat of being put into collections. It's the most common approach by billers to receive payment on something to close their book without actually fixing whatever the issue was in the first place.