H34.8121 ICD-10-CM Code: Central retinal vein occlusion, left eye, with retinal neovascularization

H34.8121 is the ICD-10-CM diagnosis code for central retinal vein occlusion, left eye, with retinal neovascularization. H34.8121 sits in the ICD-10-CM chapter for diseases of the eye and adnexa (h00-h59), within the section covering disorders of choroid and retina (h30-h36).

Under the CMS-HCC V28 risk adjustment model, H34.8121 maps to Proliferative Diabetic Retinopathy and Vitreous Hemorrhage (HCC 298) with a community, non-dual, aged base RAF weight of 0.209. H34.8121 was not retained as a payment HCC under the older V24 model, so V28 introduced or recategorized it during the 2024–2026 phase-in. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.

Coders should report H34.8121 only when the provider documentation supports the specific condition described, since more specific codes within the same hierarchy can capture additional clinical detail and may carry a higher RAF weight. Because H34.8121 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.