Excludes1 pair

H27.0- vs Z98-

H27.0 and Z98 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 H27.0
cataract extraction status (Z98.4-)
H27.0

Aphakia

Not billable
Chapter 7
Diseases of the eye and adnexa
Section
H25-H28
Use when the record says
  • Acquired absence of lens
  • Acquired aphakia
  • Aphakia due to trauma
Indexed under
  • Aphakia (acquired) (postoperative)
Z98

Other postprocedural states

Not billable
Chapter 21
Factors influencing health status and contact with health services
Section
Z77-Z99

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