H51.21 (Internuclear ophthalmoplegia, right eye) compared with H51.22 (Internuclear ophthalmoplegia, left eye), from the official CMS tabular data. H51.21 and H51.22 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. H51.21 and H51.22 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.
| H51.21Internuclear ophthalmoplegia, right eye | H51.22Internuclear ophthalmoplegia, left 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 | Internuclear ophthalmoplegia, right eye is a billable ICD-10-CM diagnosis code (H51.21). | Internuclear ophthalmoplegia, left eye is a billable ICD-10-CM diagnosis code (H51.22). |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources