Looking Ahead: Practicing Radiation Oncology in the Era of ICD-10

For over 30 years, the International Statistical Classification of Diseases and Related Health Problems, 9th edition (ICD9) has provided a framework for medical coding in the United States (1). Beginning October 1, 2015, physicians in the United States are required to begin using the updated, more complex version of this framework for the coding of morbidity: International Statistical Classification of Diseases and Related Health Problems, 10th edition (ICD-10). This much-anticipated transition has already occurred in many countries, and as the implementation date has now arrived in the United States, we summarize the changes specific to radiation oncology, highlight implications for future practice and research, and suggest useful references for radiation oncologists. The World Health Organization has been updating the ICD since 1948 (2). ICD-10 represents the 10th edition of this infrastructure. In the United States, ICD-10 was adopted for mortality coding in 1999 (3), but ICD-9 has continued to provide a framework for morbidity coding. The United States adopted 2 versions of ICD-10 on October 1, 2015: ICD-10 Clinical Modification (ICD-10CM), a set of inpatient and outpatient diagnostic codes, replacing ICD-9-CM Volumes 1 and 2, and ICD-10 Procedure Coding System (ICD-10-PCS), a set of inpatient procedure codes, replacing ICD-9-CM Volume 3. The Current Procedural Terminology (CPT) codes assigned to outpatient procedures are not a part of this transition (4). Collectively, ICD-10-CM and ICD-10-PCS will have an impact on diagnostic and procedural coding for all