P28.0 vs Q33.6
P28.0 and Q33.6 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on Q33.6
pulmonary hypoplasia associated with short gestation (P28.0)
P28.0
Primary atelectasis of newborn
Billable
- Chapter 16
- Certain conditions originating in the perinatal period
- Section
- P19-P29
Use when the record says
- Primary failure to expand terminal respiratory units
- Pulmonary hypoplasia associated with short gestation
- Pulmonary immaturity NOS
Indexed under
- Apneumatosis, newborn
- Nonexpansion, lung (newborn)
- Nonpneumatization, lung NEC
- Atelectasis › primary (massive) (partial) (pressure) (pulmonary)
- Failure, failed › expansion terminal respiratory units
Q33.6
Congenital hypoplasia and dysplasia of lung
Billable
- Chapter 17
- Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
- Section
- Q30-Q34
Indexed under
- Dysplasia › lung, congenital
- Hypoplasia, hypoplastic › lung
- Hypoplasia, hypoplastic › pulmonary
- Undeveloped, undevelopment › lung
- Development › imperfect, congenital › lungs
These two codes sit in different chapters of the Tabular List, which is usually the clearest signal that they describe different underlying processes rather than different degrees of the same one.
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