H21.331 (Parasitic cyst of iris, ciliary body or anterior chamber, right eye) compared with H21.339 (Parasitic cyst of iris, ciliary body or anterior chamber, unspecified eye), from the official CMS tabular data. H21.331 and H21.339 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. H21.331 and H21.339 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.
| H21.331Parasitic cyst of iris, ciliary body or anterior chamber, right eye | H21.339Parasitic cyst of iris, ciliary body or anterior chamber, 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 iris, ciliary body or anterior chamber, right eye is a billable ICD-10-CM diagnosis code (H21.331). | Parasitic cyst of iris, ciliary body or anterior chamber, unspecified eye is a billable ICD-10-CM diagnosis code (H21.339). |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources