Responding to pressure from physician organizations, CMS will extend by two years the deadline to re-enroll 1.4 million health care professionals that it had previously set at March 2013.  However, the extension will not affect practices that have already received a revalidation notice.  Failing to revalidate within the designated timeframe will cause a physician's enrollment record to be deactivated. The first set of revalidation notices were sent to those who bill for Medicare services but are not in CMS's electronic enrollment record, typically doctors who have not updated their enrollment in several years. [The AMA recommends that physicians periodically check CMS’s list of providers who have been contacted for revalidation to ensure that they have not missed a revalidation notice from their Medicare Administrative Contractor (MAC).  To view this list, visit https://www.cms.gov/medicareprovidersupenroll/11_revalidations.asp and click on “Revalidation Phase 1 Listing.”]