FY2027
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Excludes1 pair

A50.5- vs K00.2

A50.5 and K00.2 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 K00.2
abnormalities of teeth due to congenital syphilis (A50.5)
A50.5

Other late congenital syphilis, symptomatic

Not billable
Chapter 1
Certain infectious and parasitic diseases
Section
A50-A64
Use when the record says
  • Any congenital syphilitic condition specified as late or manifest two years or more after birth.
K00.2

Abnormalities of size and form of teeth

Billable
Chapter 11
Diseases of the digestive system
Section
K00-K14
Use when the record says
  • Concrescence of teeth
  • Fusion of teeth
  • Gemination of teeth
  • Dens evaginatus
  • Dens in dente
  • Dens invaginatus
  • Enamel pearls
  • Macrodontia
Indexed under
  • Concrescence (teeth)
  • Dens evaginatus, in dente or invaginatus
  • Dichotomy, teeth
  • Enamel pearls
  • Enameloma

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