Question 1

What is ICD-10 code H40?

Accepted Answer

H40 is the ICD-10-CM diagnosis code for Glaucoma. It belongs to the ICD-10-CM chapter for diseases of the eye and adnexa (h00-h59). H40 is a non-billable header code that organizes more specific child codes; the actual diagnosis on a claim must use one of those children. H40 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 H40 an HCC code?

Accepted Answer

H40 is a non-billable header code, so it cannot itself be a payment HCC. Header codes organize more specific child codes that share the same root concept; one of those children may map to a payment HCC under the CMS-HCC V28 or V24 risk adjustment model. Coders should select a child code from the H40 hierarchy that matches the documented presentation, then check that specific child for HCC status.

Question 3

Is H40 billable?

Accepted Answer

No. H40 is a header (non-billable) ICD-10-CM code. Header codes sit at a higher level of the diagnosis hierarchy and exist to organize a family of more specific child codes. Per ICD-10-CM coding guidelines, a header code cannot be reported on a claim as the diagnosis, coders must select a billable child code from the H40 hierarchy that matches the highest level of specificity supported by the provider's documentation. Payers reject header codes submitted as the primary diagnosis.

HCC Buddy Code Card

H40

What This Code Means

Excludes 1, Do NOT code together

Child Codes

Code Hierarchy

Open H40 in the Interactive Encoder

H40 ICD-10-CM Code: Glaucoma