Oh yes it is! I know exactly what my insurance company's negotiated prices are (because I pay them!) and they are astronomical. I just had an emergency visit and the nominal charge was $1700. The negotiated charge was $1500. That's _nothing_. I added up the medicare schedule prices for the entire visit and it was about $350. So, yes, a large insurance plan (like medicare) seems to be able to negotiate far better than my insurance company.