Neurosurgery Coding Alert
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ICD-10: Ignoring External Cause Codes Could Cost You


- Published on Wed, Apr 26, 2017

Look to V, W, X, and Y for the alphabet soup of these codes.

No medical practice likes to deal with delayed or denied claims, but if you aren’t using all of the diagnoses applicable to your patient’s condition, you could be facing these problems head-on. One way that neurosurgery coders can help their claims sail through the processing system is to embrace the external cause codes in the ICD-10 manual.

In last month’s issue of Neurosurgery Coding Alert, you discovered the ins and outs of reporting the Z codes for “Factors influencing health status and contact with health services.” After reading that article, several subscribers wrote and asked about the preceding four sections, the V, W, X, and Y codes in ICD-10. Get to know how this section of your diagnosis coding manual can assist you in describing exactly what the neurosurgeon addressed.

Don’t Use As Primary Diagnoses

Without a doubt, the codes in the “External Causes of Morbidity” section of the ICD-10 manual are helpful for claims processing purposes, but the first rule about using these codes is that they should never be listed as the primary diagnosis code. Instead, use the external cause code as secondary codes to provide additional information. Although the codes aren’t payment codes, they explain “how the injury or health condition happened (cause), the intent (unintentional or accidental; or intentional, such as suicide or assault), the place where the event occurred, the activity of the patient at the time of the event, and the person’s status (e.g., civilian, military),” according to the ICD-10 manual.

Correct coding requires you to report this added information. “ICD-10 instructs you to code an encounter to the highest specificity possible,” says Allison Anderson, owner of AAA Billing in Newark, N.J. Use the following examples to help guide your usage of the external cause codes.

You’ll Often Use These for Injuries

Most external cause codes are applicable to injuries, the ICD-10 manual states. “When you use these codes as a supplement to your primary diagnoses, you’re giving the insurer a clear picture of what happened to a patient,” Anderson says.

Example: A patient sustains minor injuries on the job after falling from a ladder while painting a house. After receiving medical attention in the emergency department for cuts and bruises, the patient continues to show signs of dizziness with drowsiness. Concerned that the patient may have head injuries, the neurosurgeon on staff admits the patient to observational status. In this case, the surgeon may include dizziness/giddiness (R42) and drowsiness (R40.0), among others, as the primary diagnoses, with W11.XXXA (Fall on and from ladder, initial encounter) linked to the primary procedure code (e.g., 99219,  Initial observation care, per day, for the evaluation and management of a patient ...) as a secondary diagnosis.

External Cause Codes Can Describe Device Failures

Although less common, neurosurgeons may also report external cause codes when medical devices are associated with adverse incidents and the practice is called on to address the resulting condition.

Example: The physician inserts a neurostimulator, but the patient has an adverse reaction and the neurosurgeon has to remove it. The neurosurgeon would first report the ICD-10 code that reflects the specific adverse reaction that the patient had, followed by Y75.2 (Prosthetic and other implants, materials and neurological devices associated with adverse incidents) to show the payer the reason for the device removal.

Look to External Causes for Reasons Behind Chronic Conditions

In other cases, you might see a patient for a work-related condition, and the worker’s compensation insurer requires you to use external cause codes to describe what happened.

Example: You see a patient for carpal tunnel syndrome of the right wrist, which is caused by her typing on her computer at work for ten hours a day, and you determine that she requires surgery. You report the diagnosis code for carpal tunnel syndrome (G56.01, Carpal tunnel syndrome, right upper limb), followed by Y93.C1 (Activity, computer keyboarding).

Although at first glance, coders might assume Y93.C1 only applies to injuries that happen during a keyboarding session, the ICD-10 manual specifically says, “These codes are appropriate for us for both acute injuries … and conditions that are due to the long-term, cumulative effects of an activity.”



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