The Centers for Medicare and Medicaid Services (CMS) recently reissued guidance on some specific issues involved in the transition to ICD-10-CM for services provided on/after October 1, 2015. Of particular interest to anesthesiologists, the guidance addresses the circumstance in which a service begins on September 30, 2015 and runs into October 1, 2015. CMS confirms that, “Anesthesia procedures that begin on 9/30/2015 but end on 10/1/2015 are to be billed with ICD-9 diagnosis codes and use 9/30/2015 as both the FROM and THROUGH date.” Further, CMS also clarifies that it will not accept and process both ICD-9-CM and ICD-10-CM codes for services provided on/after October 1, 2015. Please see MLM Matters® Number SE1408 (revised) at http://www.cms.gov/Outreach-and-Education/Medicare-Learning-Network-MLN/MLNMattersArticles/Downloads/SE1408.pdf for more information.