Chronic lower respiratory diseases (J40-J4B) ICD-10-CM
The J40–J4B section covers chronic lower respiratory diseases with 54 ICD-10-CM diagnosis codes, of which 40 are billable in fiscal year 2027. The section is organized into the 9 code ranges listed below.
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
- bronchitis due to chemicals, gases, fumes and vapors J68.0
Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
- cystic fibrosis E84
Code Ranges in This Section 9 ranges · 54 codes
The info icon previews the code ranges inside each row and its instructional notations from the official Tabular List.
About the J40–J4B Code Range
These conditions affect the lungs and airways. They include bronchitis, which is inflammation of the large airways, and bronchiectasis, a persistent widening of those airways.
J40 identifies bronchitis not specified as acute or chronic. J41 separates named forms of chronic bronchitis, while J42 is unspecified chronic bronchitis. J43 divides emphysema by its named forms and includes an unspecified form.
J44 distinguishes chronic obstructive pulmonary disease with a lower respiratory infection or flare-up from other and unspecified forms. J45 separates asthma by intermittent or persistent symptoms and by severity. J47 separates bronchiectasis with an infection or flare-up from uncomplicated bronchiectasis.
J4A distinguishes restrictive allograft syndrome from other and unspecified chronic lung allograft dysfunction. J4B identifies pulmonary mycetoma.
FY 2027 changes: The FY 2027 ICD-10-CM update, effective October 1, 2026, added J4B.
Questions About This Page
How many codes are in the J40-J4B range?
The J40-J4B range contains 54 ICD-10-CM diagnosis codes in FY 2027. 40 of them are billable, and the rest are category headers that organize the section.
What conditions does J40-J4B cover?
The range covers chronic lower respiratory diseases. The code ranges listed above break it into groups of related conditions, and each one links to its own page with the full code list.
Related References
Source: CMS FY 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
