Alphabetic Index FY2027

J42

Unspecified chronic bronchitis

FY2027Chapter 10: Diseases of the respiratory system/J40–J4B Chronic lower respiratory diseases

BillableComplete code, valid to report
Care settingsHome Health Primary · MMTA - Respiratory

J42 is a billable ICD-10-CM diagnosis code for unspecified chronic bronchitis. It is part of the FY2027 code set, effective October 1, 2026. The Alphabetic Index lists it under 11 entries. Its coding notes include a Use additional code instruction, a Code also instruction, 7 Excludes1 entries and 10 Excludes2 entries.

Use additional code

Add the listed code as a secondary code, if known.

This 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)
Also from chapter/block level (7 notes)
Inherited from Chapter 10 Diseases of the respiratory system
  • code, where applicable, 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)

Code also

Two codes may be needed to describe the condition. This note gives no sequencing order.

This code
  • , if applicable, chronic respiratory conditions due to chemicals, gases, fumes and vapors (J68.4)

Excludes1

Not coded here. The listed conditions generally should not be reported together.

This code
  • 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.-)
Also from chapter/block level (1 note)
Inherited from J40–J4B Chronic lower respiratory diseases
  • bronchitis due to chemicals, gases, fumes and vapors (J68.0)

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

Also from chapter/block level (10 notes)
Inherited from J40–J4B Chronic lower respiratory diseases
Inherited from Chapter 10 Diseases of the respiratory system
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • smoke inhalation (T59.81-)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Care settings

How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.

Home Health Primary

Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the MMTA - Respiratory clinical group.

Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026

Inclusion terms

Conditions classified to this code.

This code
  • Chronic bronchitis NOS
  • Chronic tracheitis
  • Chronic tracheobronchitis

Notes

Also from chapter/block level (1 note)
Inherited from Chapter 10 Diseases of the respiratory system
  • When a respiratory condition is described as occurring in more than one site and is not specifically indexed, it should be classified to the lower anatomic site (e.g. tracheobronchitis to bronchitis in J40).

Alphabetic Index terms

Terms the official Alphabetic Index lists for this code. 11 entries