Doesn’t matter, it’s all of them.
It's the majority of them, but there are exceptions. I switched to Blue Shield (not Blue Cross or one of the combined companies in some states) and had almost zero problems. They paid my claims accurately the vast majority of the time and fixed the occasional problem with relatively little fuss. The Blue Shield reps also knew their stuff and I never once had to explain my policy to them.
Health Net is deliberately designed from the bottom up to refuse legitimate claims and to fight tooth and nail when customers demand they follow their own contract. IMO Health Net should be shut down.
...my wife basically made this her daytime job calling about the bills and learning about how billing and coding works.
I had to do the same, despite recovering from surgery. To make matters worse, after I hit the maximum out of pocket amount the medical centers continued to send bills showing I owed a balance. It took nearly a year and repeated escalation to their executive and legal departments to get them to provide refunds. Calls, faxes and certified letters were completely ignored.
Corporate America has become quasi-legal and well-funded organized crime.
The worst of the medical centers that knowingly overcharged me was USC Keck in L.A. They completely ignored calls, emails, faxes and certified letters for nearly a year - never once responding to anything. The scumbags actually sent my account to collections despite my having a zero balance because they flatly refused to credit my overpayments. I've learned to refuse payment of any medical bill before making absolutely sure I owe the company what they are billing, and that can take months.
The thing that amazes me with all of these companies is they expect you and I to be right on top of our accounts, respond to letters and calls, and pay their bills within 30 days. This despite the fact they don't give a fuck about doing the same. My attitude has become the same as theirs: "fuck 'em, let them wait". I get sternly worded bills with red "Past Due" printed on them every month, ignore them completely and pay when I'm ready. There's been no downside.