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J42 ICD-10-CM Code: Unspecified chronic bronchitis

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FY 2026 Apr update / Diseases of the respiratory system (J00-J99) / Chronic lower respiratory diseases (J40-J4A)

J42

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

Unspecified chronic bronchitis

A long-term inflammation of the airways without specification of the type of mucus production or other distinguishing characteristics.

Buddy the Bee presenting code insight

Buddy Insight

Unspecified chronic bronchitis is used when the provider documents chronic bronchitis without specifying whether the sputum is mucoid, purulent, or mixed.

CMS-HCC V28

HCC 280

RAF 0.319

CMS-HCC V24

HCC 111

RAF 0.335

ACA/HHS

0

0

RAF 0

ESRD/PACE

0

0

RAF 0

RXHCC

HCC 229

RAF 0.0

Code Trumping

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Code Book Path

Official
J4Chronic lower respiratory diseases (J40-J4A)
J42Unspecified chronic bronchitis

Inclusion Terms

Official
  • Chronic bronchitis NOS
  • Chronic tracheitis
  • Chronic tracheobronchitis

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for J42 in this effective period.

Related Child Codes

Official

ICD-10-CM does not list child codes under J42 for this display context.

Includes

Official

ICD-10-CM does not list Includes notes for J42 in this effective period.

Excludes 1

Official
  • bronchiolitis obliterans and bronchiolitis obliterans syndrome (J44.81)
  • chronic asthmatic bronchitis (J44.-)
  • chronic bronchitis with airways obstruction (J44.-)
  • chronic emphysematous bronchitis (J44.-)
  • chronic obstructive pulmonary disease NOS (J44.9)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for J42 in this effective period.

Use Additional

Official
  • code to identify:
  • exposure to environmental tobacco smoke (Z77.22)
  • exposure to tobacco smoke in the perinatal period (P96.81)
  • history of tobacco dependence (Z87.891)
  • occupational exposure to environmental tobacco smoke (Z57.31)

Code Also

Official

ICD-10-CM does not list Code Also instructions for J42 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance
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

MEAT Support

HCC Buddy guidance
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

Audit Caution

HCC Buddy guidance
Coding J42 when the documentation actually specifies the type of sputum — always use J41.0, J41.1, or J41.8 when specified
Confusing J40 (bronchitis not specified as acute or chronic) with J42 (chronic bronchitis) — J40 does not carry HCC weight
Assuming chronic bronchitis when the provider only documents 'bronchitis' without specifying chronicity
Not querying for COPD when chronic bronchitis is present with airflow obstruction on pulmonary function testing

Common Mistakes

HCC Buddy guidance
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

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is J42 an HCC code?

Yes. J42 maps to Chronic Obstructive Pulmonary Disease, Interstitial Lung Disorders, and Other Chronic Lung Disorders under the CMS-HCC V28 risk adjustment model (and Chronic Obstructive Pulmonary Disease under V24).

HCC Category Mapping

V28HCC 280, Chronic Obstructive Pulmonary Disease, Interstitial Lung Disorders, and Other Chronic Lung Disorders
0.319
V24HCC 111, Chronic Obstructive Pulmonary Disease
0.335
RxHCCHCC 229, COPD and Chronic Bronchitis
0.000

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.

Work J42 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

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.

Coder workflow notes

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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, Interstitial Lung Disorders, and Other Chronic Lung Disorders (HCC 280) with a community, non-dual, aged base RAF weight of 0.319. Under the older CMS-HCC V24 model, J42 maps to Chronic Obstructive Pulmonary Disease (HCC 111) with a community, non-dual, aged base RAF weight of 0.335. 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

  • •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
  • •Use only when the specific type of chronic bronchitis cannot be determined from documentation

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

  • bronchiolitis obliterans and bronchiolitis obliterans syndrome (J44.81)
  • chronic asthmatic bronchitis (J44.-)
  • chronic bronchitis with airways obstruction (J44.-)
  • chronic emphysematous bronchitis (J44.-)
  • chronic obstructive pulmonary disease NOS (J44.9)
  • simple and mucopurulent chronic bronchitis (J41.-)

Use Additional Code

  • code to identify:
  • exposure to environmental tobacco smoke (Z77.22)
  • exposure to tobacco smoke in the perinatal period (P96.81)
  • history of tobacco dependence (Z87.891)
  • occupational exposure to environmental tobacco smoke (Z57.31)
  • tobacco dependence (F17.-)
  • tobacco use (Z72.0)

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

Code Hierarchy

└J42Unspecified chronic bronchitis
└J42Unspecified chronic bronchitis

Because J42 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score.

J42 maps to CMS-HCC V28 category 280, Chronic Obstructive Pulmonary Disease, Interstitial Lung Disorders, and Other Chronic Lung Disorders. See the ICD-10 to HCC mapping hub for how the V28 crosswalk works.

More on J42

Referenced in blog posts

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