J95.4 vs O74.0
J95.4 and O74.0 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.
Chemical pneumonitis due to anesthesia
- Chapter 10
- Diseases of the respiratory system
- Section
- J95
- Mendelson's syndrome
- Postprocedural aspiration pneumonia
- Mendelson's syndrome (due to anesthesia)
- Pneumonitis › postanesthetic (acute) (primary)
- Pneumonitis › postoperative (acute) (primary)
- Pneumonia › aspiration › postprocedural (acute) (double) (migratory) (purulent) (septic) (unresolved)
- Pneumonitis › chemical › due to anesthesia (acute) (primary)
Aspiration pneumonitis due to anesthesia during labor and delivery
- Chapter 15
- Pregnancy, childbirth and the puerperium
- Section
- O60-O77
- Inhalation of stomach contents or secretions NOS due to anesthesia during labor and delivery
- Mendelson's syndrome due to anesthesia during labor and delivery
- Mendelson's syndrome › in labor and delivery (due to anesthesia)
- Mendelson's syndrome › obstetric (due to anesthesia)
- Syndrome › acid pulmonary aspiration, obstetric
- Syndrome › Mendelson's
- Pneumonitis › aspiration › obstetric (acute) (primary)
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