H33.121 (Parasitic cyst of retina, right eye) compared with H33.129 (Parasitic cyst of retina, unspecified eye), from the official CMS tabular data. H33.121 and H33.129 code the same condition on opposite sides.
Same condition; these differ only in which side is documented.
These codes share a category and title and differ only in the side affected. The documentation decides which applies, and a bilateral code is reported only where the code set provides one.
Source: ICD-10-CM tabular list (laterality variant derived from the code title)
Same condition, opposite side. H33.121 and H33.129 name the same condition on opposite sides of the body.
Same category and title, differing only in which side is affected — the documentation decides which one applies, and a bilateral code is reported only where the code set provides one.
| H33.121Parasitic cyst of retina, right eye | H33.129Parasitic cyst of retina, unspecified eye | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | H00-H59 — Diseases of the Eye and Adnexa (H00-H59) | H00-H59 — Diseases of the Eye and Adnexa (H00-H59) |
| Definition | Parasitic cyst of retina, right eye is a billable ICD-10-CM diagnosis code (H33.121). | Parasitic cyst of retina, unspecified eye is a billable ICD-10-CM diagnosis code (H33.129). |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources