Still trying to figure out exactly what your role should be in Medicare's Accountable Care Organization initiative? You might want to hurry. CMS has announced 89 new ACOs serving 1.2 million Medicare beneficiaries in 40 states and Washington, D.C. A total of 2.4 million benes are receiving care from 154 ACOs overall under the program, CMS's Acting Administrator Marilyn Tavenner says in a release. Nearly half of the ACOs are "physician-driven organizations serving fewer than 10,000 beneficiaries," CMS notes. "Smaller organizations are interested in operating as ACOs."