Question 1

What is ICD-10 code H10.422?

Accepted Answer

H10.422 is the ICD-10-CM diagnosis code for Simple chronic conjunctivitis, left eye. It belongs to the ICD-10-CM chapter for diseases of the eye and adnexa (h00-h59). H10.422 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. H10.422 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Question 2

Is H10.422 an HCC code?

Accepted Answer

No. H10.422 is a billable ICD-10-CM code but does not map to any payment HCC category under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can still be reported on Medicare Advantage encounter data submissions, but it does not contribute to the beneficiary's Risk Adjustment Factor (RAF) score and therefore does not affect the risk-adjusted capitation payment to the plan. V28 reached 100% phase-in for payment year 2026.

Question 3

Is H10.422 billable?

Accepted Answer

Yes. H10.422 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. H10.422 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Question 4

What is the V28 vs V24 difference for H10.422?

Accepted Answer

H10.422 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither model rewards H10.422 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a payment HCC.

Question 5

What should coders know when reporting H10.422?

Accepted Answer

Verify laterality is documented in the medical record - this code specifically indicates the left eye, so ensure the provider has specified which eye is affected Distinguish between simple chronic conjunctivitis and other types (allergic, infectious, chemical) as each has different code assignments; simple conjunctivitis lacks these specific etiologies

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H10.422

Is H10.422 an HCC code?

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Open H10.422 in the Interactive Encoder

H10.422 ICD-10-CM Code: Simple chronic conjunctivitis, left eye

HCC Buddy Code Card

H10.422

Is H10.422 an HCC code?

What This Code Means

Coding Tips

Child Codes

Code Hierarchy

Open H10.422 in the Interactive Encoder