Physicians may opt out, not MCOs.

Abstract

Physicians and other practitioners can now contract privately with Medicare beneficiaries for services that Medicare covers and charge more than Medicare pays. Private contracting means more treatment choices for beneficiaries. It also means that practitioners can charge whatever the market will bear, but at the cost of having to withdraw from Medicare for 2 years. For private contracting to become popular, the law will have to be changed to lower the associated cost.