ICD10BillableValid for clinical use

ICD-10 Code H40.20: Unspecified primary angle-closure glaucoma

H40.20 is a billable ICD-10 diagnosis code used to classify Unspecified primary angle-closure glaucoma in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the eye and adnexa (H00-H59).

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the eye and adnexa (H00-H59).

When is it used?

  • May be used when a clinician documents unspecified primary angle-closure glaucoma in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.

Code hierarchy

chapter
7Diseases of the eye and adnexa (H00-H59)
block
H40-H42Glaucoma
category
H40Glaucoma
category
H40.2Primary angle-closure glaucoma
currentH40.2

Official coding notes

7th character notes
  • One of the following 7th characters is to be assigned to code H40.20 to designate the stage of glaucoma
  • stage unspecified
  • mild stage
  • moderate stage
  • severe stage
  • indeterminate stage

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Related specialists

Ophthalmologist

Coding guidelines

Common synonyms

Unspecified primary angle-closure glaucoma

Frequently asked questions

Code details

CodeH40.20
SystemICD10
Display nameUnspecified primary angle-closure glaucoma
ChapterDiseases of the eye and adnexa (H00-H59)
BlockGlaucoma

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

ICD-10 Code H40.20 for Unspecified primary angle-closure glaucoma | HealthAssure