Home Health ICD-9/ICD-10 Alert

Question: When reporting an asthma diagnosis, do I need a fifth digit?

Answer: Yes. ICD-9 requires you to use a fifth-digit subclassification with asthma codes (493.xx). If you submit four digits for an asthma diagnosis, payers will reject the ICD-9 code as truncated or incomplete.

Correct method: Assign the fourth digit based on the asthma category:

• 493.0x--Extrinsic asthma
• 493.1x--Intrinsic asthma
• 493.2x--Chronic obstructive asthma
• 493.9x--Asthma, unspecified.

Then, identify the asthma's current state with the appropriate fifth digit:

• 0--... unspecified
• 1--... with status asthmaticus
• 2--... with (acute) exacerbation.

The most common type of asthma for Medicare home health patients is chronic obstructive asthma coded in subcategory 493.2.

Don't stop yet: A final digit of "1" indicates that the patient has status asthmaticus, which is a medical emergency and is usually treated in the emergency department, not at home. Assign a "2" for patients whose asthma is now exacerbated (in other words, something has caused the condition to flare up). Otherwise, use a fifth digit of "0." Code 493.x0 is appropriate when the patient's asthma is controlled.

Unless otherwise indicated, reader questions were answered by Lisa Selman-Holman, JD, BSN, RN, HCS-D, COS-C, consultant and principal of Selman-Holman & Associates in Denton, TX.