H21.56
⚠ Non-billable (Header)Pupillary abnormalities
Diseases of the eye and adnexa (H00-H59)
⚠️ This is a category header code — not billable. Use a more specific child code below.
Also Known As
❌ Excludes1
directThese codes are mutually exclusive. Never code them together.
- • congenital deformity of pupil (Q13.2-)
Child Codes (4)
Clinical Description
ICD-10-CM code H21.56 represents pupillary abnormalities. This code falls under the Diseases of the eye and adnexa (H00-H59) classification. It is a non-billable category header code. A more specific child code from the list below must be used for billing and reimbursement purposes.
This is a 6-character code at the 5th level of specificity. There are 4 more specific child codes under H21.56. Coders should note that H21.56 has 2 Excludes1 restriction(s) — codes that cannot be reported together on the same claim.
Frequently Asked Questions
What is ICD-10 code H21.56?
ICD-10-CM code H21.56 is "Pupillary abnormalities". It belongs to the category: Diseases of the eye and adnexa (H00-H59).
Is H21.56 a billable ICD-10 code?
No, H21.56 is a non-billable header code. A more specific child code must be used for billing.
What codes are excluded with H21.56?
H21.56 has 2 Excludes1 rule(s). These codes are mutually exclusive and cannot be coded together on the same claim.
Can H21.56 be coded with other codes?
H21.56 has 1 Excludes2 note(s). These conditions can be coded together if both are documented in the patient record.
Related Codes in H21.5
Other codes in the same category that may be relevant for differential coding:
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Data Source
CMS ICD-10-CM 2026 Tabular List
Updated October 1, 2025 (FY2026)