American Academy of Professional Coders (AAPC) Practice Exam 2026 - Free AAPC Practice Questions and Exam Prep Guide

ICD-10-CM officially became effective on October 1, 2013. This transition marked a significant change in the coding system used for diagnoses and inpatient procedures in the United States, moving from ICD-9 to ICD-10. The implementation was aimed at improving the accuracy of coding and enhancing the quality of health data collected.

Prior to this date, the healthcare industry operated under ICD-9, which had limitations in terms of the number of codes available and the specificity of those codes. Adopting ICD-10-CM allowed for a greater level of detail in medical coding, accommodating advancements in medical technology and treatment practices.

The other dates provided in the options do not correspond to the correct implementation date of ICD-10-CM. January 1, 2012, was not associated with any major changes in the coding system. April 1, 2015, and December 1, 2014, are also incorrect as those dates fall after the official effective date, which created confusion as the systems continued to evolve post-implementation. Understanding the correct date is crucial for professionals in the healthcare and coding fields as it directly impacts compliance and the use of coding in practice.