The transition from the ICD-9 medical coding system to the ICD-10 coding system took place on October 1, 2015. Depending on who you talk to, the changes are either viewed as an improvement over the former system, or a necessary evil.
In a nutshell, the ICD-9 code sets that were used for medical diagnoses and inpatient procedures are now replaced by ICD-10 code sets. The new codes were needed because the Centers for Medicare and Medicaid (CMS) felt that the 30-year-old ICD-9 codes were outdated and inconsistent with current medical practice. The structure of the ICD-9 codes also limited their utility as many of the ICD-9 categories were full, and new codes could not be added. Coding for a diagnosis in the ICD-10-CM system uses 3 to 7 digits instead of 3 to 5 that were used with ICD-9-CM. Similarly, ICD-10-PCS coding for inpatient hospital procedures uses 7 alphanumeric digits instead of 3 or 4 numeric digits used under the old ICD-9-PCS procedure coding. Coding under ICD-10-PCS is now more specific than ICD-9-PCS coding.
ICD-10 affects the procedures for coding patients’ diagnoses and inpatient procedures by healthcare providers and entities covered by the Health Insurance Portability and Accountability Act (HIPAA), not just those who submit Medicare and Medicaid claims. The change to ICD-10 does not affect CPT coding for outpatient procedures. More information about ICD-10 can be found on the CMS website at www.cms.gov/ICD10.