H20.812 Fuchs' heterochromic cyclitis, left eye

ICD-10-CM Diagnosis Code H20.812: Fuchs' heterochromic cyclitis, left eye

ICD-10-CM code H20.812 identifies Fuchs' heterochromic cyclitis of the left eye, classified as a disease or syndrome under the parent category H20.81. Clinical literature distinguishes this condition by iris heterochromia, fine diffuse keratic precipitates, and posterior subcapsular cataracts. The code appears in payer guidance and terminology systems. 1 2 4 5

Plain-language overview

Code H20.812 designates Fuchs' heterochromic cyclitis affecting the left eye, providing a specific diagnostic label for this ocular condition within the ICD-10-CM terminology system. 1

What this code represents

The terminology record classifies H20.812 with the semantic type of disease or syndrome, establishing it as an active concept within the ICD-10-CM version 2026 system. 1

Coding details

Code H20.812 is a child concept of H20.81, Fuchs' heterochromic cyclitis, and exists alongside related codes specifying right eye, bilateral, and unspecified eye presentations. 1 6

Clinical context

Clinical literature differentiates Fuchs heterochromic iridocyclitis from Posner Schlossman syndrome by noting iris heterochromia, fine abnormal angle vessels, diffuse keratic precipitates, and posterior subcapsular cataracts. 2

Documentation considerations

The official display label for H20.812 explicitly specifies Fuchs' heterochromic cyclitis of the left eye, distinguishing it from codes for the right eye, bilateral, or unspecified eye. 1 6

Coverage and utilization context

A Medicare billing and coding article for ophthalmology posterior segment imaging includes the code H20.812 within its text for Fuchs' heterochromic cyclitis. 4

What the sources add

While the National Cancer Institute record provides the official terminology definition, the FHIRsmith value set demonstrates the integration of H20.812 into standardized healthcare interoperability systems. 1 5

The clinical reference excerpt discusses left eye uveitis and glaucomatous damage, while the terminology record strictly defines the code, showing a distinction between clinical descriptions and official code assignments. 1 2

Questions to verify

Reviewers may verify whether the clinical documentation describes findings of iris heterochromia, fine abnormal angle vessels, diffuse keratic precipitates, and posterior subcapsular cataracts associated with this condition. 2

Sources

1. ICD-10-CM H20.812 terminology record — National Cancer Institute Enterprise Vocabulary Services; accessed 2026-07-27.
2. Bookshelf — ncbi.nlm.nih.gov; accessed 2026-07-27.
3. Phecode 371.1 · Cancer PRSweb — csg.sph.umich.edu; accessed 2026-07-27.
4. Article - Billing and Coding: Ophthalmology: Posterior Segment Imaging (Extended Ophthalmoscopy and Fundus Photography) (A57071) — cms.gov; accessed 2026-07-27.
5. FHIRsmith: ValueSet/ValueSet-2.16.840.1.113762.1.4.1047.552.json — packages2.fhir.org; accessed 2026-07-27.
6. ICD-10-CM 2024 | H20 - Iridocyclitis — unboundmedicine.com; accessed 2026-07-27.