ICD10BillableValid for clinical use

ICD-10 Code H42: Glaucoma in diseases classified elsewhere

H42 is a billable ICD-10 diagnosis code used to classify Glaucoma in diseases classified elsewhere 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 26 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 glaucoma in diseases classified elsewhere 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
currentH40-H42

Official coding notes

Applicable to
  • underlying condition, such as:
  • amyloidosis (E85.-)
  • aniridia (Q13.1)
  • glaucoma (in) diabetes mellitus (E08.39, E09.39, E10.39, E11.39, E13.39)
  • Lowe's syndrome (E72.03)
  • Rieger anomaly (Q13.81)
  • specified metabolic disorder (E70-E88)
Excludes1 (do not code together)
  • glaucoma (in) onchocerciasis (B73.02)
  • glaucoma (in) syphilis (A52.71)
  • glaucoma (in) tuberculous (A18.59)
  • neovascular secondary angle closure glaucoma (H40.84-)
Code first
  • underlying condition, such as:
  • amyloidosis (E85.-)
  • aniridia (Q13.1)
  • glaucoma (in) diabetes mellitus (E08.39, E09.39, E10.39, E11.39, E13.39)
  • Lowe's syndrome (E72.03)
  • Rieger anomaly (Q13.81)
  • specified metabolic disorder (E70-E88)

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

Related codes

Sibling codes

Coverage-related procedures and services

CPT 92083high
VISUAL FIELD EXAMINATION, UNILATERAL OR BILATERAL, WITH INTERPRETATION AND REPORT; EXTENDED EXAMINATION (EG, GOLDMANN VISUAL FIELDS WITH AT LEAST 3 ISOPTERS PLOTTED AND STATIC DETERMINATION WITHIN THE CENTRAL 30 DEG, OR QUANTITATIVE, AUTOMATED THRESHOLD PERIMETRY, OCTOPUS PROGRAM G-1, 32 OR 42, HUMPHREY VISUAL FIELD ANALYZER FULL THRESHOLD PROGRAMS 30-2, 24-2, OR 30/60-2)
Source: CMS coverage guidance
CPT 92082high
VISUAL FIELD EXAMINATION, UNILATERAL OR BILATERAL, WITH INTERPRETATION AND REPORT; INTERMEDIATE EXAMINATION (EG, AT LEAST 2 ISOPTERS ON GOLDMANN PERIMETER, OR SEMIQUANTITATIVE, AUTOMATED SUPRATHRESHOLD SCREENING PROGRAM, HUMPHREY SUPRATHRESHOLD AUTOMATIC DIAGNOSTIC TEST, OCTOPUS PROGRAM 33)
Source: CMS coverage guidance
CPT 92081high
VISUAL FIELD EXAMINATION, UNILATERAL OR BILATERAL, WITH INTERPRETATION AND REPORT; LIMITED EXAMINATION (EG, TANGENT SCREEN, AUTOPLOT, ARC PERIMETER, OR SINGLE STIMULUS LEVEL AUTOMATED TEST, SUCH AS OCTOPUS 3 OR 7 EQUIVALENT)
Source: CMS coverage guidance
CPT 92133high
COMPUTERIZED OPHTHALMIC DIAGNOSTIC IMAGING (EG, OPTICAL COHERENCE TOMOGRAPHY [OCT]), POSTERIOR SEGMENT, WITH INTERPRETATION AND REPORT, UNILATERAL OR BILATERAL; OPTIC NERVE
Source: CMS coverage guidance
CPT 92134high
COMPUTERIZED OPHTHALMIC DIAGNOSTIC IMAGING (EG, OPTICAL COHERENCE TOMOGRAPHY [OCT]), POSTERIOR SEGMENT, WITH INTERPRETATION AND REPORT, UNILATERAL OR BILATERAL; RETINA
Source: CMS coverage guidance
CPT 92137high
COMPUTERIZED OPHTHALMIC DIAGNOSTIC IMAGING (EG, OPTICAL COHERENCE TOMOGRAPHY [OCT]), POSTERIOR SEGMENT, WITH INTERPRETATION AND REPORT, UNILATERAL OR BILATERAL; RETINA, INCLUDING OCT ANGIOGRAPHY
Source: CMS coverage guidance

Coding guidelines

Compatibility

Legacy and official ICD code match exactly.
Legacy codes
H42

Common synonyms

Glaucoma in diseases classified elsewhere

Frequently asked questions

Code details

CodeH42
SystemICD10
Display nameGlaucoma in diseases classified elsewhere
ChapterDiseases of the eye and adnexa (H00-H59)
BlockGlaucoma

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
GlaucomaGlaucomaGlaucomaGlaucomaGlaucomaGlaucoma

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 H42 for Glaucoma in diseases classified elsewhere | HealthAssure