Some physicians have sued plans for deselection, claiming their due process rights were denied because they were not given the same procedure as would be applicable in medical staff peer review proceedings. These cases failed because nongovernmental hospitals do not have to provide due process as a matter of right. They are only required to provide whatever due process they contract for in their medical staff bylaws. Hospitals provide extensive due process because they want to be able to claim immunity under HCQIA. MCOs, as insurers, are not subject to antitrust lawsuits, and are much harder to attack under the other theories used to attack peer review determinations. This means that they do not need the immunity provided by HCQIA so they have no need to provide the due process necessary to qualify for its protections. The courts also rejected claims that HCQIA itself created a cause of action for physicians denied due process, holding that it has no purpose beyond providing immunity for properly conducting peer review.