There is no short answer to the question of whether HMOs are immune from lawsuit in malpractice situations. HMO doctors may be sued personally, but the problem arises when you try to sue the HMO corporation. Nationwide this issue is being battled every day in state and federal courts. HMOs often claim that a federal statute, known as ERISA, has preempted all state medical malpractice laws that might apply to them. Some courts have agreed with that and some courts have not. Many courts have said it depends on exactly how you describe the case that you are bringing.
Florida courts are still hammering out the issue of HMO immunity just like the courts elsewhere. For the most part, Florida courts, including Florida’s federal courts, have indicated that if HMOs are sued for providing negligent care they may be liable. On the other hand, if they are sued because of a decision made internally regarding what medical procedures the insurance plan will or will not PAY for, they may have immunity. These laws and cases are constantly evolving and if you have a dispute with an HMO you should try to find a law firm with experience in handling HMO disputes.