Following CMS' proposed rule that would give some accountable care organizations (ACOs) a three-year reprieve before they receive penalties for failure to meet performance measures, 89 new ACOs will join the Medicare Shared Savings Program (MSSP), the Centers for Medicare & Medicaid Services announced in a blog post this week. The new ACOs will bring the total participating in the MSSP to 405 next year, with more than 7.2 million beneficiaries, according to Center for Medicare Deputy Administrator Sean Cavanaugh. It also adds 23,000 new providers in the program, according to the post, in addition to the roughly17,000 new providers that joined the MSSP in 2014. >> Read the full report from FierceHealthcare