H40-H42
Medium Complexity

Glaucoma

Primary Specialty: Ophthalmology
Last Updated: 2025-09-09

ICD-10 Codes (1)

1 billable
0 category headers
H42
Billable
Glaucoma in diseases classified elsewhere
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Updates & Changes

FY 2026 Updates

Current Year

Deleted Codes

No codes deleted in this range for FY 2026

No significant changes for FY 2026

This range maintains stability with current coding practices

Historical Changes

  • FY 2025: Routine maintenance updates with minor terminology clarifications
  • FY 2024: Enhanced specificity requirements for certain code ranges
  • FY 2023: Updated documentation guidelines for improved clarity

Upcoming Changes

  • Proposed updates pending review by Coordination and Maintenance Committee
  • Under consideration: Enhanced digital health integration codes

Implementation Guidance

  • Review all FY 2026 updates for H40-H42 codes before implementation
  • Always verify the most current codes in the ICD-10-CM manual
  • Ensure clinical documentation supports the selected diagnosis codes
  • +3 more guidance items...

Range Overview

high priority

The ICD-10 code range H40-H42 pertains to Glaucoma, a group of eye conditions that damage the optic nerve, often due to abnormally high pressure in the eye. This range includes codes for primary, secondary, and congenital glaucoma, as well as glaucoma associated with systemic syndromes. The codes are used to specify the type, cause, and severity of the glaucoma, and whether it is bilateral or unilateral.

Key Usage Points:

  • Always code for the highest level of specificity, indicating the type and cause of glaucoma.
  • Use additional codes to identify any associated systemic conditions.
  • Specify whether the glaucoma is bilateral or unilateral, and if unilateral, which eye is affected.
  • Indicate the stage of glaucoma: early, moderate, advanced, or indeterminate.
  • For patients with both primary and secondary glaucoma, code for each condition separately.

Coding Guidelines

When to Use:

  • When a patient is diagnosed with primary open-angle glaucoma.
  • When a patient has secondary glaucoma due to an eye injury.
  • When a patient has congenital glaucoma.
  • When a patient has glaucoma associated with a systemic syndrome.
  • When a patient has glaucoma with increased episcleral venous pressure.

When NOT to Use:

  • When a patient has ocular hypertension without glaucoma.
  • When a patient has a history of glaucoma but no current diagnosis.
  • When a patient has a family history of glaucoma but no personal diagnosis.
  • When a patient has dry eye syndrome, which is not a form of glaucoma.
  • When a patient has age-related macular degeneration, which is not a form of glaucoma.

Code Exclusions

Always verify exclusions with the latest ICD-10-CM official guidelines and the patient's medical record.

Documentation Requirements

Documentation for glaucoma should include a clear diagnosis, the type and cause of glaucoma, whether it is bilateral or unilateral, and the stage of the disease. Any associated systemic conditions should also be documented.

Clinical Information:

  • Clear diagnosis of glaucoma
  • Type and cause of glaucoma
  • Whether the glaucoma is bilateral or unilateral
  • Stage of glaucoma
  • Any associated systemic conditions

Supporting Evidence:

  • Eye examination findings
  • Visual field testing results
  • Imaging studies
  • Patient's symptom history
Good Documentation Example:

Patient diagnosed with moderate primary open-angle glaucoma in the right eye, confirmed by eye examination and visual field testing.

Poor Documentation Example:

Patient has glaucoma.

Common Documentation Errors:

  • Not specifying the type and cause of glaucoma
  • Not indicating whether the glaucoma is bilateral or unilateral
  • Not documenting the stage of glaucoma
  • Not documenting any associated systemic conditions

Range Statistics

2
Total Codes
1
Billable
Complexity:
Medium
Primary Use:Clinical Documentation
Chapter:

Coding Complexity

Medium
Complexity Rating

Coding for glaucoma can be complex due to the need to specify the type and cause of the disease, identify any associated systemic conditions, and indicate whether the glaucoma is bilateral or unilateral and the stage of the disease. However, with thorough documentation, these factors can be accurately coded.

Key Factors:
  • Determining the type and cause of glaucoma
  • Identifying any associated systemic conditions
  • Specifying whether the glaucoma is bilateral or unilateral
  • Determining the stage of glaucoma

Specialty Focus

Glaucoma codes are primarily used by ophthalmologists and optometrists. They may also be used by primary care physicians and endocrinologists when managing patients with systemic conditions that can cause glaucoma, such as diabetes.

Primary Specialties:
Ophthalmology
70%
Optometry
20%
Endocrinology
10%
Clinical Scenarios:
  • A patient with diabetes develops secondary glaucoma.
  • A patient presents with symptoms of acute angle-closure glaucoma.
  • A patient is diagnosed with congenital glaucoma.
  • A patient with a systemic syndrome develops associated glaucoma.
  • A patient with primary open-angle glaucoma has a routine follow-up visit.

Resources & References

Resources for coding glaucoma include the ICD-10-CM official guidelines, clinical reference books, and educational materials from professional coding organizations.

Official Guidelines:

  • ICD-10-CM Official Guidelines for Coding and Reporting
  • American Academy of Ophthalmology ICD-10 Coding Resources
  • American Optometric Association ICD-10 Resources

Clinical References:

  • Clinical Ophthalmology: A Systematic Approach
  • The Wills Eye Manual: Office and Emergency Room Diagnosis and Treatment of Eye Disease

Educational Materials:

  • American Health Information Management Association (AHIMA) ICD-10 Training
  • American Academy of Professional Coders (AAPC) ICD-10 Training

Frequently Asked Questions

How do I code for bilateral glaucoma?

If the type and stage of glaucoma are the same in both eyes, use a bilateral code. If they are different, use separate codes for each eye.

How do I code for glaucoma associated with a systemic condition?

First code for the systemic condition, then use an additional code from the H40-H42 range to specify the type and cause of the glaucoma.