To ensure complete and accurate coding, healthcare providers must update or replace the ICD-9-CM codebooks as new codes are implemented and existing codes are amended or deleted. In addition, encoders and other coding software must also be updated at least yearly.
ICD-9-CM Diagnostic Codes
ICD-9-CM diagnostic codes represent the reasons why patients require and/or seek medical care.
Each numerical code represents a specific symptom, condition, injury, or disease. ICD-9-CM diagnostic codes in the main classification (codes 001 through 999) consist of three, four, or five digits. The first three numbers represent a specific diagnosis, and one or two additional numbers may follow a decimal point after the three-number code to provide information that is more specific.
Example: Code 562.13 represents a diagnosis of diverticulitis of the colon with intestinal hemorrhaging. The first three numbers (562) indicate a diagnosis of diverticula of the intestine; the number 1 after the decimal point represents the location of the diverticula, the colon; and the fifth digit represents the most specific diagnosis: diverticulitis of colon with hemorrhage.
Supplementary ICD-9-CM Codes
ICD-9-CM includes two supplementary classifications. Alphanumeric codes from the supplementary classifications provide additional information about the patient and/or the circumstances surrounding the patient’s illness or injury. V codes (V01 through V85) represent the various factors that may influence the patient’s health status and contact with health services. E codes (E800 through E999) represent the external factors that cause injuries and poisonings. Diagnostic Coding
The Central Office on ICD-9-CM maintains the official coding guidelines for diagnostic coding.
The guidelines require ICD-9-CM code assignments to be as specific as possible and to be supported by health record