Claims to be from Multiplan (health insurance entity) wanting to "verify" medical provider information.  When I told them we didn't give out information over the phone, but would need a written request along with authorization from the provider,  he told me he just wanted to "verify" what they had, and he could probably get it from the hospital website, to which I replied "then you probably should do that since we won't be able to respond over the phone" at which point he hung up on me.  This group calls our office at least 3 times per week from various numbers trying to get doctor's information.  We never, ever give them anything.  What with all the MEDICARE/MEDICAID fraud these days, no reputable insurance company would operate this way.  Not to mention, of course, since any hospital and most doctor's offices have contracts for participation in managed care plans, they would be doing updates periodically if they wanted to be paid.  Bunch of losers.

MultiPlan (MPI) is not an insurance company. They are a network of providers for hundred of insurance companies, they also price claims for hundreds of insurance companies. MPI is a very reputable company, and is the largest network of provider's in the US.  
You are most likely getting calls from MPI because you are balance billing patients for discounts taken through the network when they shouldn't be and they are trying to get the issue straightened out for the patient, or the insurance company has requested help in getting an issue resolved.
If a proviider has a contract with MPI, then there is no violation as there is a contract between the 2 and MPI can request information. If 3rd party biller, than there is the PHI issue, and of course HIPPA etc.
Many providers balance bill their patients for discounts that the providers have agreed to accept. THAT IS FRAUD. It is up to MPI to try and get this straightened out for the insurance company, so their member will not be penalized, therefore MultiPlan contacts the provider's office/facility to review/educate and discuss with the provider and/or billing dept.
If someone hung up on you, that is unacceptable- I think "Bunch of losers" is a bit much.

Why would I, a private individual, get a call from MultiPlan on my work cell phone (which I have not distributed) when I have no disputed insurance claims medical or otherwise.  There were no calls to my home phone nor my personnal cell which I have given out.  Doesn't make any sense based upon what Dre says about the function of MPI.

Got call from what turned out to be MultiPlan.  Missed the call, so reverse dialed and got greeting.  That is how I know it was Multiplan.  Have no insurance disputes, so have no idea what the call was about.  Also not sure why it was placed to my work-related cell phone number which I do not distribute unless work related.  I am not a provider of anything so do not know "services" MPI could be checking up on.