J42
BillableUnspecified chronic bronchitis
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is J42 an HCC code?
Yes. J42 maps to Chronic Obstructive Pulmonary Disease under the CMS-HCC V28 risk adjustment model (and Chronic Obstructive Pulmonary Disease 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 J42
For J42to 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 J42 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
J42 is the ICD-10-CM diagnosis code for unspecified chronic bronchitis. A long-term inflammation of the airways without specification of the type of mucus production or other distinguishing characteristics. J42 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).
Under the CMS-HCC V28 risk adjustment model, J42 maps to Chronic Obstructive Pulmonary Disease (HCC 280) with a community, non-dual, aged base RAF weight of 0.334. The V24 model used during the PY2024–PY2025 transition mapped J42 the same way and at the same RAF weight. 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 non-specific chronic bronchitis code; query the provider for more detail about sputum characteristics to use J41.0, J41.1, or J41.8. Because J42 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 J42 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
Clinical Significance
Unspecified chronic bronchitis is used when the provider documents chronic bronchitis without specifying whether the sputum is mucoid, purulent, or mixed. While it carries the same HCC mapping as the specified subtypes, coders should query for specificity when possible to improve documentation quality.
Documentation Requirements
- ✓Provider documentation explicitly stating 'chronic bronchitis'
- ✓Duration criteria met: cough with sputum production for at least 3 months in 2 consecutive years
- ✓Current symptom status and any exacerbations
- ✓Treatment plan for chronic bronchitis management
- ✓Exclusion of other causes of chronic cough
Excludes 1 — Do NOT code together
Use Additional Code
Commonly Confused Codes
- •J41.0 — Simple chronic bronchitis: preferred when mucoid sputum is specified
- •J41.1 — Mucopurulent chronic bronchitis: preferred when purulent sputum is specified
- •J40 — Bronchitis, not specified as acute or chronic: does NOT map to an HCC; must specify chronicity
- •J44.9 — COPD, unspecified: use when COPD with airflow obstruction is documented
- •J20.9 — Acute bronchitis, unspecified: completely different condition, acute not chronic