I can tell you, firsthand, that your interpretation is correct. One year they wouldn't cover my much needed procedures because they were diagnostic. I went out of pocket for them. Two years later and they wouldn't cover them because they were routine. What a joke. I will say that I've had two injuries stemming from an accident in the 12 or so years that I've been with them. They take good care of someone when they've been involved in an accident.
Predatory insurance needs to end. The answer isn't handing control over to the government. That would only take us out of the frying pan and into the fire.
