The Centers for Medicare & Medicaid Services (CMS) reports that "The 2014 Annual Participation Enrollment Program allows eligible physicians, practitioners, and suppliers an opportunity to change their participation status by December 31, 2013. Due to the later than usual release of the Medicare Physician Fee Schedule Final Rule, CMS is extending the 2014 annual participation enrollment period through January 31, 2014. Therefore, participation elections and withdrawals must be post-marked on or before January 31, 2014. The effective date for any participation status changes elected by providers during the extension remains January 1, 2014"