Everyone is familiar with the external cause codes in ICD-10. We have hear examples of walking into a lamppost, bitten by a turtle, or a water skier injured due to water skis on fire. These examples provide some levity, but many of these examples exist in ICD-9 and will rarely be used in ICD-10.
Today, I want to look at an area of ICD-10 coding (and ICD-9 coding) that is more dangerous and very common in physician practices; unspecified codes.
Unspecified codes exist in ICD-9, but many people do not realize these unspecified codes also exist in ICD-10. Unspecified codes are used by many practices to save space on their paper superbill, where there is not room to list out all of the available (and more specific) code choices. As a result, some of the most commonly used codes in ICD-9 are unspecified codes.
If you have converted your most frequently used ICD-9 codes to ICD-10 codes, your conversion analysis may be underestimating the difficulty of transitioning to ICD-10 because of these unspecified codes. Most applied mapping tools take an ICD-9 code and show all of the potential options in ICD-10, but these tools typically do not show ICD-10 choices that would be more appropriately associated with a more specific ICD-9 code.
For example, a practice may have 715.96 – OA Knee on their superbill. The long description of this code is actually Osteoarthrosis, unspecified whether generalized or localized, lower leg. A mapping tool may show this as a simple 1 to 1 conversion, with the resulting ICD-10 code being M17.9 – Osteoarthrosis of knee, unspecified.
The potential problem in this example is that ICD-10 has 10 additional osteoarthosis of the knee codes that are more specific. Most in the industry agree that the entire point of migrating to ICD-10 is to provide more detail to provide better health outcomes and ultimately reduce healthcare expenses. The question is how will payers respond when a claim is submitted with this unspecified code, rather than a more specific ICD-10 code that identifies whether the osteoarthrosis was primary or secondary? Or which knee: right, left or both?
Payers have never adjudicated ICD-10 claims and will be learning as they go. We do not know how payers will handle these unspecified codes, but practices need to be prepared to respond as they get feedback from the payers. An additional complication is that all payers will not handle these codes the same way at the same time.
To protect cash flow, practices should examine which unspecified codes are frequently used in their practice today and be prepared to use more specific ICD-10 codes if and when they are required by their payers.