United Health Care does not question a procedure if doctor deams it necessary. If I suspect or he/she suspects XYZ--they do the lab work or whatever for XYZ to make sure it is or is not XYZ.
Usually experimental stuff is excluded---so an experimental drug that may help with a condition--until it is mainstream it may not be covered (not suer exactly what the plan says).
My beef is my limitations on PT/chiro--I need PT twice this year--but met my limit and even though it was for two separate injuries in two separate parts of the year--I paid out of pocket for the second one. But that is not my insurance's fault--it is the plan that my employer paid for. I suppose I could go otu on my own and get a better plan...but it would cost me more...and not enough to justify the PT costs. However--for an accident that would require months of therapy--I'd be toast. Luckily--I did find out that you can refuse to file with insurance and my PT gave us the medicare rate

They have to charge the insurance higher b/c the insurance stiffs them so much on what they are worth. But when you pay cash--they charge you the real rate. very interesting! So if it is really worth $90 of their time..they risk losing money if they charge insurance that much.
Anywho---so my beef is with my employer for the plan they chose--not insurances fault.
and I like our insurer--b/c they do not question the Doc's (now if Doc has habit of doing unnecessary things consistently--then they will evaluate the Doc and what they are doing).