Excludes1 pair
J40 vs J45-
J40 and J45 are not coded together. ICD-10-CM declares them mutually exclusive with an Excludes1 note — the two conditions are not expected to occur together, so exactly one of them is normally correct for a given encounter. The Official Guidelines carve out one exception: if the two conditions are clearly unrelated to each other, both may be reported.
The official note, declared on J40
asthmatic bronchitis NOS (J45.9-)
J40
Bronchitis, not specified as acute or chronic
Billable
- Chapter 10
- Diseases of the respiratory system
- Section
- J40-J4B
Use when the record says
- Bronchitis NOS
- Bronchitis with tracheitis NOS
- Catarrhal bronchitis
- Tracheobronchitis NOS
Indexed under
- Bronchitis (diffuse) (fibrinous) (hypostatic) (infective) (membranous)
- Bronchitis › catarrhal (l5 years of age and above)
- Bronchitis › with › tracheitis (l5 years of age and above)
- Tracheitis › with › bronchitis (15 years of age and above)
J45
Asthma
Not billable
- Chapter 10
- Diseases of the respiratory system
- Section
- J40-J4B
Use when the record says
- allergic (predominantly) asthma
- allergic bronchitis NOS
- allergic rhinitis with asthma
- atopic asthma
- extrinsic allergic asthma
- hay fever with asthma
- idiosyncratic asthma
- intrinsic nonallergic asthma
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027