H10.3 vs P39.1
H10.3 and P39.1 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 H10.3
ophthalmia neonatorum NOS (P39.1)
H10.3
Unspecified acute conjunctivitis
Not billable
- Chapter 7
- Diseases of the eye and adnexa
- Section
- H10-H11
Indexed under
- ConjunctivitisNOS › acute (staphylococcal) (streptococcal)
P39.1
Neonatal conjunctivitis and dacryocystitis
Billable
- Chapter 16
- Certain conditions originating in the perinatal period
- Section
- P35-P39
Use when the record says
- Neonatal chlamydial conjunctivitis
- Ophthalmia neonatorum NOS
Indexed under
- Blennorrhea › inclusion (acute) (chronic)
- ConjunctivitisNOS › infantile (staphylococcal) (streptococcal)
- ConjunctivitisNOS › neonatal (staphylococcal) (streptococcal)
- Dacryocystitis › neonatal
- Inclusion › blennorrhea
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