ICD 10 Coding Alert

Question: I’m wondering what external cause coding will look like in ICD-10. Could you provide an example?

Massachusetts Subscriber

Answer: The Cooperating Parties for ICD-10-CM/PCS and ICD-9-CM Coding recently issued a clarification stating that external cause reporting guidelines won’t change with the new code set. But your coding for these situations in ICD-10 will look entirely different from your ICD-9 coding.

Scenario: Suppose your patient had no hypertension diagnosis. But he continues to experience elevated blood pressure while taking blood pressure medication. While assessing the patient, the home health nurse discovers he was taking his medication once daily instead of twice daily because of the cost of the drug. To code for this patient in ICD-10, you would list:

• I10 (Essential [primary] hypertension);
• T46.5x6D (Underdosing of other antihypertensive drugs, subsequent encounter); and
• Z91.120 (Patient’s intentional underdosing of medication regimen due to financial hardship).