H27.0 vs Z98.4
H27.0 and Z98.4 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 Z98.4
aphakia (H27.0)
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)
Z98.4
Cataract extraction status
Not billable
- Chapter 21
- Factors influencing health status and contact with health services
- Section
- Z77-Z99
Indexed under
- Cataract › extraction status (cortical) (immature) (incipient)
- Status › cataract extraction (post)
- Absence › lens › post cataract extraction (of) (organ or part) (complete or partial)
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