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E84.0 ICD-10-CM Code: Cystic fibrosis with pulmonary manifestations

E84.0 maps to CMS-HCC V28 277. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · HCC coding software

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Code lookupE84.0

FY 2026 Apr update / Endocrine, nutritional and metabolic diseases (E00-E89) / Metabolic disorders (E70-E88)

E84.0

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

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.

Buddy the Bee presenting code insight

Buddy Insight

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.

OverviewRisk ModelsCode BookDocumentationAuditNotesEdition comparison

CMS-HCC V28

HCC 277

Coefficient HCC 277: 0.998 (Community Non-Dual Aged (CNA))

CMS-HCC V24

Historical

Historical

Not used for CY2026 payment

ACA/HHS

HCC 159

Code-level coefficient reference

ESRD/PACE

HCC 110

Code-level coefficient reference

RXHCC

HCC 225

Code-level coefficient reference

Code Book Path

Official
E84Cystic fibrosisE84.0Cystic fibrosis with pulmonary manifestations

Inclusion Terms

Official

No inclusion terms are included in this display for E84.0. Check the code and parent instructions in the Code Book.

Excludes 2

Official
  • Ehlers-Danlos syndromes (Q79.6-)Inherited from E70-E88

Related Codes

Official
E84.1Cystic fibrosis with intestinal manifestationsE84.8Cystic fibrosis with other manifestationsE84.9Cystic fibrosis, unspecified

Includes

Official
  • mucoviscidosisInherited from E84

Excludes 1

Official
  • transitory endocrine and metabolic disorders specific to newborn (P70-P74)Inherited from E00-E89, E70-E88
  • androgen insensitivity syndrome (E34.5-)Inherited from E00-E89, E70-E88
  • congenital adrenal hyperplasia (E25.0)Inherited from E00-E89, E70-E88
  • hemolytic anemias attributable to enzyme disorders (D55.-)Inherited from E00-E89, E70-E88
  • Marfan syndrome (Q87.4-)Inherited from E00-E89, E70-E88
  • 5-alpha-reductase deficiency (E29.1)Inherited from E00-E89, E70-E88

Code First

Official

No Code First sequencing instructions are included in this display for E84.0. Check the code and parent instructions in the Code Book.

Use Additional

Official
  • code to identify any infectious organism present, such as:
  • Pseudomonas (B96.5)

Code Also

Official
  • exocrine pancreatic insufficiency (K86.81)Inherited from E84

Buddy Documentation Tip

HCC Buddy guidance
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)

MEAT Support

HCC Buddy guidance
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)

Audit Caution

HCC Buddy guidance
Defaulting to unspecified E84.9 when pulmonary manifestations are clearly documented
Not recognizing that cystic fibrosis patients with lung involvement should receive E84.0 even if other manifestations are also present — code all applicable manifestation codes
Coding bronchiectasis (J47) separately without recognizing it as a cystic fibrosis pulmonary manifestation included in E84.0
Missing the opportunity to code multiple CF manifestation codes when both pulmonary and GI involvement are documented

Common Mistakes

HCC Buddy guidance
E84.9 — Cystic fibrosis, unspecified: use only when manifestation type is unknown; E84.0 is preferred when pulmonary involvement is documented
E84.11 — Meconium ileus in cystic fibrosis: GI manifestation, not pulmonary
E84.19 — Cystic fibrosis with other intestinal manifestations: GI-focused manifestation
E84.8 — Cystic fibrosis with other manifestations: for non-pulmonary, non-intestinal manifestations

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is E84.0 an HCC code?

Yes. E84.0 (Cystic fibrosis with pulmonary manifestations) maps to HCC 277, Cystic Fibrosis under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 0.998. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.

Coder answer: E84.0 is billable and maps to V28 HCC 277, Cystic Fibrosis. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code
E84.0
Description
Cystic fibrosis with pulmonary manifestations
HCC (V28)
HCC 277 — Cystic Fibrosis
RAF reference coefficient
0.998
Billable
Yes
Payment year
2026

HCC Category Mapping

V28HCC 277, Cystic Fibrosis
0.998
ESRDHCC 110, Cystic Fibrosis
Not separately weighted
RxHCCHCC 225, Cystic Fibrosis
Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work E84.0 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for E84.0

For E84.0, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.

  • 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

Coder workflow notes

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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 source-labeled community, non-dual, aged reference coefficient of 0.998. No V24 mapping is shown for E84.0; use the applicable model and payment year when reviewing the V28 mapping. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.

Use this code when cystic fibrosis primarily manifests with pulmonary symptoms; document specific lung complications separately if present. For E84.0, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule. 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, source-labeled coefficient references, 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.

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)

Commonly Confused Codes

  • •E84.9: Cystic fibrosis, unspecified: use only when manifestation type is unknown; E84.0 is preferred when pulmonary involvement is documented
  • •E84.11: Meconium ileus in cystic fibrosis: GI manifestation, not pulmonary
  • •E84.19: Cystic fibrosis with other intestinal manifestations: GI-focused manifestation
  • •E84.8: Cystic fibrosis with other manifestations: for non-pulmonary, non-intestinal manifestations
  • •J47.9: Bronchiectasis, uncomplicated: if caused by cystic fibrosis, use E84.0 instead

Child Codes

E84.0Cystic fibrosis with pulmonary manifestations
HCC 277
E84.1Cystic fibrosis with intestinal manifestations
E84.8Cystic fibrosis with other manifestations
HCC 277
E84.9Cystic fibrosis, unspecified
HCC 277

Code Hierarchy

└E84Cystic fibrosis└E84.0Cystic fibrosis with pulmonary manifestations
└E84.0Cystic fibrosis with pulmonary manifestations

Also searched as

  • E84 0
  • E840

For E84.0, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.

E84.0 maps to CMS-HCC V28 category 277, Cystic Fibrosis. See the ICD-10 to HCC mapping hub for how the V28 crosswalk works. The mapping identifies a payment HCC category for E84.0. Review its source-labeled HCC coefficient above, check the RAF Calculator with complete member context for CMS-HCC V28 PY2026, and confirm the documentation the chart needs before the code is submitted. HCC Buddy shows no RAF score unless every required source and calculation check passes.

Work E84.0 in HCC Buddy

Open E84.0 in the Code Book for the full Index-to-Tabular path, MEAT checklist, and V28 HCC mapping, or in the Encoder to code from a keyword search. Pro includes 7 days to try everything, no card required.

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