ICD-10 C23 Conversion to ICD-9 156.0

ICD-10 to ICD-9 Crossover Result

ICD-10 Code C23 representing "Malignant neoplasm of gallbladder" can be backward-mapped to its ICD-9 equivalent 156.0: "Malig neo gallbladder". This is a direct match with no additional mapping qualifiers. The absence of a flag generally means the mapping is considered exact or precise. In other words, the ICD-10 code maps cleanly to the ICD-9 code without qualification, approximation, or needing multiple codes. This conversion was generated using the latest General Equivalence Mappings (GEMs). While these mappings provide a standardized reference, not all ICD-10 codes have an exact ICD-9 match. Review the table below carefully and consider the clinical context when interpreting the mapped codes.

ICD‑10 Code

C23

Malignant neoplasm of gallbladder

ICD‑9 Code

156.0

Malig neo gallbladder

– This is a direct match with no additional mapping qualifiers.
ICD‑10 Code

I82.C23

Chronic embolism and thombos of int jugular vein, bilateral

ICD‑9 Code

453.76

Ch embl internl jug vein

Approximate Flag – This ICD-10 code does not have an exact ICD-9 equivalent. The matched code is the closest available option and may not fully capture the original diagnosis.

About the General Equivalence Mappings Crossover Tool

The General Equivalence Mappings tool is a standardized crossover resource developed by the Centers for Medicare & Medicaid Services (CMS) and the National Center for Health Statistics (NCHS). It was created to help healthcare providers, coders, payers, and software vendors accurately transition between ICD-9 and ICD-10 diagnosis codes.

This ICD-10 to ICD-9 crosswalk tool supports both forward and backward mapping, making it valuable for converting legacy data, conducting audits, updating medical coding systems, and ensuring compliance with ICD-10 standards. GEMs are especially helpful when analyzing historical claims, aligning reimbursement logic, or migrating between systems.

Because not all ICD codes have a direct match, users should interpret each mapping carefully. Some ICD-10 to ICD-9 conversions may require clinical judgment or additional documentation to ensure coding accuracy. Not all ICD-10 to ICD-9 code conversions result in a single, exact match. In some cases, an ICD-10 code may map to multiple ICD-9 codes, especially when the original diagnosis requires more than one code to fully capture its meaning in the older coding system.