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J84.112 ICD-10-CM Code: Idiopathic pulmonary fibrosis

J84.112 maps to CMS-HCC V28 278. A source-labeled RAF reference is available. Documentation must support MEAT. MEAT criteria · RAF Calculator · HCC coding software

ICD-10-CM Code View

HCC Buddy Code Card

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FY 2026 Apr update / Diseases of the respiratory system (J00-J99) / Other respiratory diseases principally affecting the interstitium (J80-J84)

J84.112

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

Idiopathic pulmonary fibrosis

A progressive lung disease of unknown cause where lung tissue becomes scarred and stiff, making breathing increasingly difficult.

Buddy the Bee presenting code insight

Buddy Insight

Idiopathic pulmonary fibrosis is a progressive, fatal lung disease with a median survival of 3-5 years from diagnosis, making it one of the highest-acuity interstitial lung diseases.

CMS-HCC V28

HCC 278

Code-level coefficient reference

CMS-HCC V24

Historical

Historical

Not used for CY2026 payment

ACA/HHS

HCC 162

Code-level coefficient reference

ESRD/PACE

HCC 112

Code-level coefficient reference

RXHCC

HCC 226

Code-level coefficient reference

Code Book Path

Official
J84.1Other interstitial pulmonary diseases with fibrosis
J84.11Idiopathic interstitial pneumonia
J84.112Idiopathic pulmonary fibrosis

Inclusion Terms

Official
  • Cryptogenic fibrosing alveolitis
  • Idiopathic fibrosing alveolitis

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for J84.112 in this effective period.

Related Child Codes

Official
J84.111Idiopathic interstitial pneumonia, not otherwise specified
J84.113Idiopathic non-specific interstitial pneumonitis
J84.114Acute interstitial pneumonitis
J84.115Respiratory bronchiolitis interstitial lung disease
J84.116Cryptogenic organizing pneumonia

Includes

Official

ICD-10-CM does not list Includes notes for J84.112 in this effective period.

Excludes 1

Official
  • lymphoid interstitial pneumonia (J84.2)
  • pneumocystis pneumonia (B59)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for J84.112 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for J84.112 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for J84.112 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance
High-resolution computed tomography showing usual interstitial pneumonia pattern OR surgical lung biopsy confirmation
Pulmonologist documentation confirming idiopathic pulmonary fibrosis diagnosis with exclusion of known causes
Pulmonary function test results showing restrictive pattern with reduced diffusion capacity
Disease severity and progression documented (forced vital capacity trend, oxygen requirements)

MEAT Support

HCC Buddy guidance
High-resolution computed tomography showing usual interstitial pneumonia pattern OR surgical lung biopsy confirmation
Pulmonologist documentation confirming idiopathic pulmonary fibrosis diagnosis with exclusion of known causes
Pulmonary function test results showing restrictive pattern with reduced diffusion capacity
Disease severity and progression documented (forced vital capacity trend, oxygen requirements)

Audit Caution

HCC Buddy guidance
Using the unspecified pulmonary fibrosis code (J84.10) when IPF has been specifically diagnosed — this loses significant HCC value
Failing to distinguish IPF from other causes of pulmonary fibrosis such as asbestosis, radiation fibrosis, or connective tissue disease-associated ILD
Not querying the provider when documentation says 'pulmonary fibrosis' without specifying idiopathic — the specificity matters enormously for risk adjustment
Coding IPF for patients under workup who have not yet had the diagnosis confirmed — requires definitive diagnosis

Common Mistakes

HCC Buddy guidance
J84.111 — Idiopathic interstitial pneumonia NOS is used when the specific IIP subtype is NOT determined; IPF (J84.112) is a distinct entity with UIP pattern
J84.170 — Interstitial lung disease with progressive fibrotic phenotype is used for progressive fibrosis in OTHER diseases classified elsewhere, not primary IPF
J84.10 — Pulmonary fibrosis unspecified does NOT map to the same high-severity HCC and should not be used when IPF is documented
J84.113 — NSIP has a better prognosis than IPF and distinct imaging/pathology pattern

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 J84.112 an HCC code?

Yes. J84.112 (Idiopathic pulmonary fibrosis) maps to HCC 278, Idiopathic Pulmonary Fibrosis and Lung Involvement in Systemic Sclerosis under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 0.818. 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: J84.112 is billable and maps to V28 HCC 278, Idiopathic Pulmonary Fibrosis and Lung Involvement in Systemic Sclerosis. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code
J84.112
Description
Idiopathic pulmonary fibrosis
HCC (V28)
HCC 278 — Idiopathic Pulmonary Fibrosis and Lung Involvement in Systemic Sclerosis
RAF reference coefficient
0.818
Billable
Yes
Payment year
2026

HCC Category Mapping

V28HCC 278, Idiopathic Pulmonary Fibrosis and Lung Involvement in Systemic Sclerosis
0.818
ESRDHCC 112, Fibrosis of Lung and Other Chronic Lung Disorders
Not separately weighted
RxHCCHCC 226, Idiopathic Pulmonary Fibrosis and Systemic Sclerosis with Lung Involvement
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 J84.112 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT Criteria for J84.112

For J84.112 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 J84.112 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

J84.112 is the ICD-10-CM diagnosis code for idiopathic pulmonary fibrosis. A progressive lung disease of unknown cause where lung tissue becomes scarred and stiff, making breathing increasingly difficult. J84.112 sits in the ICD-10-CM chapter for diseases of the respiratory system (j00-j99), within the section covering other respiratory diseases principally affecting the interstitium (j80-j84).

Under the CMS-HCC V28 risk adjustment model, J84.112 maps to Idiopathic Pulmonary Fibrosis and Lung Involvement in Systemic Sclerosis (HCC 278) with a source-labeled community, non-dual, aged reference coefficient of 0.818. No V24 mapping is shown for J84.112; use the applicable model and payment year when reviewing the V28 mapping. 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. 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.

This is a specific diagnosis requiring clinical, radiological, and often pathological confirmation. Because J84.112 maps to an HCC category, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) before the diagnosis is used for risk adjustment. 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 J84.112 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

  • •This is a specific diagnosis requiring clinical, radiological, and often pathological confirmation
  • •Document disease progression and functional status for treatment planning

Clinical Significance

Idiopathic pulmonary fibrosis is a progressive, fatal lung disease with a median survival of 3-5 years from diagnosis, making it one of the highest-acuity interstitial lung diseases. This diagnosis carries exceptional weight in risk adjustment due to the intensive resource utilization including antifibrotic therapy (nintedanib, pirfenidone), frequent monitoring, oxygen therapy, and potential lung transplant evaluation. Accurate capture is critical for reflecting the true severity burden of these patients.

Documentation Requirements

  • ✓High-resolution computed tomography showing usual interstitial pneumonia pattern OR surgical lung biopsy confirmation
  • ✓Pulmonologist documentation confirming idiopathic pulmonary fibrosis diagnosis with exclusion of known causes
  • ✓Pulmonary function test results showing restrictive pattern with reduced diffusion capacity
  • ✓Disease severity and progression documented (forced vital capacity trend, oxygen requirements)
  • ✓Current treatment plan including antifibrotic therapy, supplemental oxygen, and transplant evaluation status

Commonly Confused Codes

  • •J84.111: Idiopathic interstitial pneumonia NOS is used when the specific IIP subtype is NOT determined; IPF (J84.112) is a distinct entity with UIP pattern
  • •J84.170: Interstitial lung disease with progressive fibrotic phenotype is used for progressive fibrosis in OTHER diseases classified elsewhere, not primary IPF
  • •J84.10: Pulmonary fibrosis unspecified does NOT map to the same high-severity HCC and should not be used when IPF is documented
  • •J84.113: NSIP has a better prognosis than IPF and distinct imaging/pathology pattern

Child Codes

J84.111Idiopathic interstitial pneumonia, not otherwise specified
HCC 280
J84.112Idiopathic pulmonary fibrosis
HCC 278
J84.113Idiopathic non-specific interstitial pneumonitis
HCC 280
J84.114Acute interstitial pneumonitis
HCC 280
J84.115Respiratory bronchiolitis interstitial lung disease
HCC 280
J84.116Cryptogenic organizing pneumonia
HCC 280
J84.117Desquamative interstitial pneumonia
HCC 280

Code Hierarchy

└J84Other interstitial pulmonary diseases└J84.1Other interstitial pulmonary diseases with fibrosis└J84.11Idiopathic interstitial pneumonia└J84.112Idiopathic pulmonary fibrosis
└J84.112Idiopathic pulmonary fibrosis

Also searched as

  • IPF
  • idiopathic pulmonary fibrosis

Because J84.112 maps to an HCC category, the documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) before the diagnosis is used for risk adjustment.

J84.112 maps to CMS-HCC V28 category 278, Idiopathic Pulmonary Fibrosis and Lung Involvement in Systemic Sclerosis. See the ICD-10 to HCC mapping hub for how the V28 crosswalk works. The mapping identifies a payment HCC category for J84.112. 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.

More on J84.112

Referenced in blog posts

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