International Classification of Diseases (ICD-9)

ICD-9 is an acronym for International Classification of Diseases, 9th Revision. ICD-9 coding is a statistical classification system that arranges diseases and injuries into code categories according to established criteria.

For example, an injury such as a broken arm could be classified and coded as follows: fractured radius, 813.81 Using the broken arm example; the left, right, or bilateral (both) arms would be identified. In addition, an injury site may also be listed if necessary. Site locations apply to injuries to the fingers, teeth, and toes.

ICD-9 codes are three, four or five-digit numeric codes that represent a uniform, international classification system of coding disease and injury diagnoses and are used to report allowed, or disallowed conditions. BWC has also identified invalid ICD-9 codes that may not be used for reporting an injury/condition. Many of these invalid ICD-9 codes are not related to an industrial injury or occupational disease.

Most medical reports, hospital reports and billing statements will use ICD-9 codes to identify the injury/diagnoses. When medical providers submit bills for services, they list the ICD-9 code. BWC and the managed care organziation (MCO) review all bills to determine if the medical provider is treating the allowed conditions in the claim. If the provider submits bills for allowed conditions, they will be paid. However, a provider will not receive payment if he or she did not obtain prior authorization for the treatment plan. If the provider submits bills for injuries not allowed in the claim, they will be denied.

How does BWC use ICD-9 codes?
Since ICD-9 codes identify the type and nature of the injury, they also are used to determine what medical treatment is appropriate. For example, if a claim were allowed for a torn medial meniscus, a serious knee injury, surgery would likely be an appropriate type of treatment. However, if the claim were allowed for a sprained knee, a less serious injury, surgical intervention would not be appropriate and authorization would not be granted.

What is an “invalid ICD-9 code"?
BWC has defined the following information as a “invalid ICD-9” codes:

• A code for an injury/condition that is not causally related to an industrial injury or occupational disease.
• The proper application of coding principles (Code assignment requires the highest level of specificity i.e. must assign the maximum number of digits for a code.) BWC has identified all three and four digit codes that require a fourth and fifth digits respectively.
• An unspecified injury/condition or site code therefore a more specific code exists.
• A symptom code.
• A multiple injury/site code. Reported injuries/conditions with more than one injury/site are assigned individual codes for each.