Medical coding – ICD 9 CM coding system – Billing highest level

ICD-9-CM Coding System
 
International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes indicate the condition, symptoms, problems, complaints, diagnosis or other reasons for the visit or procedure. In other words, ICD-9 codes justify the use of CPT^® codes. You may list up to four ICD-9 codes on the Medicare claim form, but the first one used must reflect the chief reason for the services provided. Enter only one diagnosis per detail line on the electronic or paper claim. The additional diagnoses are used to describe any co-existing conditions. The chief reason and the co-existing conditions must also be noted in the medical record. Co-existing conditions requiring specific tests or procedures should also be recorded on the claim form and in the medical record.

Billing the Highest Level
 
ICD-9 codes are composed of three-, four- and five-digit numeric and alphanumeric codes. ICD-9 codes classify groups of diseases and injuries by etiology and by organ system. These codes also classify symptoms.
Diagnosis codes must always be documented to the highest known level of specificity. If a three-digit code lists four- and five-digit codes as subcodes, then the three-digit code becomes a category, not a billable code. Only those codes highlighted in bold in the example below are billable codes.
Samples of ICD-9 Levels