J66.8
BillableAirway disease due to other specific organic dusts
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is J66.8 an HCC code?
Yes. J66.8 maps to Chronic Obstructive Pulmonary Disease under the CMS-HCC V28 risk adjustment model (and Fibrosis of Lung and Other Chronic Lung Disorders under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for J66.8
For J66.8to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed J66.8 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
J66.8 is the ICD-10-CM diagnosis code for airway disease due to other specific organic dusts. A respiratory condition caused by inhaling various organic dusts not classified elsewhere, such as grain, wood, or other plant-based particles. The specific dust source should be identified when possible. J66.8 sits in the ICD-10-CM chapter for diseases of the respiratory system (j00-j99), within the section covering lung diseases due to external agents (j60-j70).
Under the CMS-HCC V28 risk adjustment model, J66.8 maps to Chronic Obstructive Pulmonary Disease (HCC 280) with a community, non-dual, aged base RAF weight of 0.334. Under the older CMS-HCC V24 model, J66.8 maps to Fibrosis of Lung and Other Chronic Lung Disorders (HCC 112) with a community, non-dual, aged base RAF weight of 0.268. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
This is a residual category; always attempt to identify and document the specific organic dust causing the disease. Because J66.8 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for J66.8 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
Clinical Significance
This residual code captures airway disease from specific organic dusts not classified elsewhere, such as grain dust, wood dust, or other plant-based particles. It is important for risk adjustment because it captures chronic occupational lung disease that may not fit named conditions like byssinosis or farmer's lung but still carries significant respiratory morbidity.
Documentation Requirements
- ✓Identification and documentation of the specific organic dust causing the condition
- ✓Explanation of why a more specific J66.0-J66.2 or J67.x code does not apply
- ✓Occupational or environmental exposure history
- ✓Chest imaging and pulmonary function test results
- ✓Current symptoms, functional status, and treatment plan
- ✓Duration and intensity of dust exposure
Commonly Confused Codes
- •J66.0 (Byssinosis) — use for cotton, flax, or hemp textile dust specifically
- •J67.x (Hypersensitivity pneumonitis codes) — different mechanism; J67 is allergic/immunologic response, J66 is airway disease
- •J66.1-J66.2 — use these when flax or cannabis dust is specifically identified
- •J68.x (Respiratory conditions due to chemicals, gases, fumes) — chemical exposure, not organic dust