The HMO subsidiary of Michigan's largest health insurer, Blue Cross Blue Shield of Michigan has begun the process to purchase an independent, Lansing-based HMO, Physicians Health Plan of Mid-Michigan. The deal faces a challenge from other HMOs who contend it will reduce competition and raise rates, but the Blue plan argues it will cut costs through synergies and pass those savings on to customers. Blue Cross Blue Shield of Michigan also operates one of the nation's largest and most advanced patient-centered medical home initiatives. It has 1,200 doctors in over 300 practices signed up, but that was the easy part. The hard part will be persuading the later adopters to change how they deliver care and accept a different payment model. As the Medicare enrollment season gets under way, Michigan seniors have evolved into two camps: those who favor a Medicare Advantage health plan, and those who favor original Medicare, stacked with perhaps a Part D prescription drug plan and a Medicare supplement product. Awareness of these different types of buyers is driving insurers to offer products they have never offered before.