Question 1

What is ICD-10 code J40?

Accepted Answer

J40 is the ICD-10-CM diagnosis code for bronchitis, not specified as acute or chronic. Inflammation of the airways in the lungs (bronchitis) without clear indication of whether it is acute or chronic in nature. J40 sits in the ICD-10-CM chapter for diseases of the respiratory system (j00-j99), within the section covering chronic lower respiratory diseases (j40-j4a).

J40 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

Query the provider to determine if bronchitis is acute or chronic, as more specific codes (J20 for acute, J41-J42 for chronic) are preferred.

Question 2

Is J40 an HCC code?

Accepted Answer

No. J40 is a billable ICD-10-CM code but does not map to any payment HCC category under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can still be reported on Medicare Advantage encounter data submissions, but it does not contribute to the beneficiary's Risk Adjustment Factor (RAF) score and therefore does not affect the risk-adjusted capitation payment to the plan. V28 reached 100% phase-in for payment year 2026.

Question 3

Is J40 billable?

Accepted Answer

Yes. J40 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. J40 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Question 4

What is the V28 vs V24 difference for J40?

Accepted Answer

J40 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither model rewards J40 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a payment HCC.

Question 5

What should coders know when reporting J40?

Accepted Answer

Query the provider to determine if bronchitis is acute or chronic, as more specific codes (J20 for acute, J41-J42 for chronic) are preferred Document the duration and characteristics of symptoms to support acute versus chronic classification

J40

Is J40 an HCC code?

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Coding Tips

Excludes 1 — Do NOT code together

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Code Hierarchy

Open J40 in the Interactive Encoder