The Centers for Medicare and Medicaid Services (CMS) recently mailed letters to all Medicare fee-for-service providers about the new Medicare Beneficiary Identifiers (MBIs) that are replacing Social Security Numbers on Medicare cards beginning April 2018. Providers should carefully review the letter to find out how to accept the new number in order to ensure their patients have continuous access to care; the letter will contain specific information for Noridian, California’s Medicare administrative contractor. For more information, go to the CMS website at