Excludes1 pair
J42 vs J44.9
J42 and J44.9 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 J42
chronic obstructive pulmonary disease NOS (J44.9)
J42
Unspecified chronic bronchitis
BillableUnspecified
- Chapter 10
- Diseases of the respiratory system
- Section
- J40-J4B
Use when the record says
- Chronic bronchitis NOS
- Chronic tracheitis
- Chronic tracheobronchitis
Indexed under
- Pharyngotracheitis, chronic
- Bronchitis › chronic
- Bronchitis › senile (chronic)
- Bronchorrhea › chronic (infective) (purulent)
- Infection, infected, infective › trachea, chronic
J44.9
Chronic obstructive pulmonary disease, unspecified
BillableUnspecified
- Chapter 10
- Diseases of the respiratory system
- Section
- J40-J4B
Use when the record says
- Chronic obstructive airway disease NOS
- Chronic obstructive lung disease NOS
Indexed under
- Disease, diseased › airway › obstructive, chronic
- Disease, diseased › lung › obstructive (chronic)
- Disease, diseased › pulmonary › chronic obstructive
- Obstruction, obstructed, obstructive › airway › chronic
- Obstruction, obstructed, obstructive › lung › disease, chronic
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