On October 1st, both the U.S. health system and the California Division of Workers’ Compensation officially adopted ICD-10 diagnosis codes.
Specifically, the California Division of Workers’ Compensation Medical Billing and Payment Guide, Section 3.0 (a)(2) states that:
Although ICD-10 coding is required on or after October 1, 2015, for a twelve month period ending October 1, 2016, no medical treatment shall be denied based solely on an error in the level of specificity of the ICD-10 diagnosis code(s) used.
But what exactly does “specificity” mean?
Take a look at our breakdown of the structure of an ICD-10-CM code.
An ICD-10-CM code is anywhere from 3 to 7 characters. The more characters present, the higher the level of specificity.
The first three characters of an ICD-10-CM code indicate the diagnosis category and the affected body part. In the example above, for characters 1-3:
- “S” indicates an injury.
- “S6” indicates an injury to the wrist, hand, and fingers.
- “S63” indicates a dislocation or a sprain to the wrist, hand, and fingers.
The second set of three characters offer further specificity about about the diagnosis: etiology, severity, laterality, and other important details that make the diagnosis even more specific. In example above, for characters 4-6:
- “S63.6” indicates an “other and unspecified” sprain.
- “S63.63” indicates a sprain of the interphalangeal joint.
- “S63.630” refers to a sprain of the interphalangeal joint of the right index finger.
Finally, the last character indicates whether the treatment was for an initial encounter, a subsequent encounter, or sequela (a complication that arises as a direct result of a condition). In the diagnosis example above:
- “A” indicates a diagnosis for an initial encounter.
Although the ICD-10 diagnosis codes guide may indicate a higher level of specificity is required, denial of a medical treatment bill based on a lack of ICD-10 code specificity is not allowed.
For California workers’ comp billing, an incorrect 4th, 5th, and 6th character--the part of the ICD-10 code that indicates increased specificity--cannot lead to a denial of a bill for treatment until October 1st, 2016.