Cracking the Code
Coding ‘Not Elsewhere Classifiable” (NEC)
- Published on
While coding ICD-10-CM, you will come across the abbreviation NEC, or ‘not elsewhere classifiable.’ This is used when the ICD-10-CM code system does not provide a code specific to the patient’s condition. Selecting a code with the NEC classification means that the provider documented more specific information regarding the patient’s condition, but there is no code in ICD-10-CM to report the condition accurately.
In our FY 2023 ICD-10-CM guidelines, I.A.6, it states, “NEC or “Not elsewhere classifiable” This abbreviation in the Alphabetic Index represents “other specified.” When a specific code is not available for a condition, the Alphabetic Index directs the coder to the “other specified” code in the Tabular List.
For example, when a provider documents that the patient has a retroperitoneal mass. If we look in our ICD-10-CM alphabetic index for the main term ‘Mass’, then we will find the sub-terms abdominal/retroperitoneal. However, we see there is no sub-term for retroperitoneal under abdominal. We do find a sub-term in the alphabetic index under Mass/abdominal for ‘specified site NEC’ leading us to ICD-10-CM code R19.09. For this situation, R19.09 would be the reported code as there is no specific code for a retroperitoneal mass.