E84.0
BillableCystic fibrosis with pulmonary manifestations
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is E84.0 an HCC code?
Yes. E84.0 maps to Cystic Fibrosis under the CMS-HCC V28 risk adjustment model (and Cystic Fibrosis 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 E84.0
For E84.0 to 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 E84.0 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
E84.0 is the ICD-10-CM diagnosis code for cystic fibrosis with pulmonary manifestations. Cystic fibrosis is a genetic disorder affecting the lungs and digestive system; this code specifically indicates lung involvement with symptoms like chronic cough and breathing difficulties. E84.0 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering metabolic disorders (e70-e88).
Under the CMS-HCC V28 risk adjustment model, E84.0 maps to Cystic Fibrosis (HCC 277) with a community, non-dual, aged base RAF weight of 0.405. Under the older V24 model, E84.0 mapped to the same category but with a base RAF weight of 0.473 — V28 recalibrated weights across the entire model. 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.
Use this code when cystic fibrosis primarily manifests with pulmonary symptoms; document specific lung complications separately if present. Because E84.0 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 E84.0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code when cystic fibrosis primarily manifests with pulmonary symptoms; document specific lung complications separately if present
- •This is the most common presentation of CF; ensure you're not using E84.9 (unspecified) if pulmonary involvement is documented
Clinical Significance
Cystic fibrosis with pulmonary manifestations is the most common presentation of this life-limiting genetic disease, involving chronic progressive lung disease with recurrent infections, bronchiectasis, and eventual respiratory failure. It carries a high RAF weight reflecting the substantial healthcare resource utilization and complexity of care.
Documentation Requirements
- ✓Confirmed diagnosis of cystic fibrosis (CFTR mutation testing or sweat chloride test)
- ✓Documentation of specific pulmonary manifestations (chronic bronchitis, bronchiectasis, recurrent pneumonias, lung function decline)
- ✓Current pulmonary function test results (FEV1)
- ✓Active treatment regimen (CFTR modulators, airway clearance, inhaled antibiotics, pancreatic enzymes)
- ✓Pulmonary exacerbation history and hospitalizations
- ✓Microbiology results (Pseudomonas, MRSA colonization status)
Use Additional Code
- code to identify any infectious organism present, such as:
- Pseudomonas (B96.5)