Doctors are the ones negotiating the rates with the insurers. In MA, really much of the northeast, a person is very loyal to their doctor, its why Massachusetts BCBS has close to 100% doctor participation, they want everyone, and they are willing to pay higher rates for it. Doctors have formed large bargaining groups to make sure they take advantage of that. If doctors request large contracts, and the insurer declines, the physician group threatens to pull out and send letters to their XX,XXX customers to tell them to find new insurance. (I've seen that done countless times). The insurer finally gives in and pays what the doctor wants, and raises insurance premiums.

If you look at states with lower doctor participation in their health plans, premiums are less. Florida Blue, I can't find the statistic right now, but I believe I saw it was in the mid 70%'s of doctors in the state participating. Florida prices insurance by age and smoking for the under 65 market, so I can't compare very well between them, so I'll compare the over 65 market where rates are the same regardless of age or smoking. The lowest price MA BCBS plan is $0 a month, the lowest Florida Blue is negative $75 a month, yes they put $75 a month into your social security check. Doctor copays, drug deductible, hospital copay, ambulance copay, it's all lower with the Florida Blue plan. Because if a doctor wants an excessive amount of money, Florida Blue, says no, we want to provide the best deal for our members. They still have doctors in every field and geographic region of the state, covering the vast majority of the doctors, but the ones who want payments that are well more than average, aren't helping medical costs, they are hurting them, so insurance companies pass on their participation. If we did that in MA, our insurance could be 10-15% cheaper, maybe even more.