2025 ICD-10-CM Diagnosis Code H42
Glaucoma in diseases classified elsewhere
- ICD-10-CM Code:
- H42
- ICD-10 Code for:
- Glaucoma in diseases classified elsewhere
- Is Billable?
- Yes - Valid for Submission
- Chronic Condition Indicator: [1]
- Chronic
- Code Navigator:
H42 is a billable diagnosis code used to specify a medical diagnosis of glaucoma in diseases classified elsewhere. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2024 through September 30, 2025.
Approximate Synonyms
The following list of clinical terms are approximate synonyms, alternative descriptions, or common phrases that might be used by patients, healthcare providers, or medical coders to describe the same condition. These synonyms and related diagnosis terms are often used when searching for an ICD-10 code, especially when the exact medical terminology is unclear. Whether you're looking for lay terms, similar diagnosis names, or common language alternatives, this list can help guide you to the correct ICD-10 classification.
- Bilateral glaucoma due to systemic syndrome
- Bilateral glaucoma of eyes due to plateau iris
- Bilateral open angle glaucoma due to vascular disorder
- Bilateral secondary angle closure glaucoma
- Glaucoma and sleep apnea syndrome
- Glaucoma due to combination of mechanisms
- Glaucoma due to congenital anomaly of eye
- Glaucoma due to diabetes mellitus
- Glaucoma due to diabetes mellitus
- Glaucoma due to diabetes mellitus type 1
- Glaucoma due to Lowe syndrome
- Glaucoma due to systemic syndrome
- Glaucoma due to systemic syndrome
- Glaucoma due to systemic syndrome
- Glaucoma due to systemic syndrome
- Glaucoma in endocrine, nutritional and metabolic diseases
- Glaucoma in endocrine, nutritional and metabolic diseases
- Glaucoma in endocrine, nutritional and metabolic diseases
- Glaucoma of left eye due to plateau iris
- Glaucoma of left eye due to systemic syndrome
- Glaucoma of right eye due to plateau iris
- Glaucoma of right eye due to systemic syndrome
- Neovascular angle closure glaucoma
- Neovascular angle closure glaucoma
- Neovascular angle closure glaucoma
- Neovascular angle closure glaucoma
- Neovascular glaucoma due to diabetes mellitus
- Neovascular glaucoma due to diabetes mellitus
- Neovascular glaucoma due to diabetes mellitus type 1
- Neovascular glaucoma due to diabetes mellitus type 2
- Open angle glaucoma due to vascular disorder
- Open angle glaucoma due to vascular disorder
- Open angle glaucoma due to vascular disorder
- Open angle glaucoma due to vascular disorder
- Open angle glaucoma of left eye due to vascular disorder
- Open angle glaucoma of right eye due to vascular disorder
- Phacomorphic secondary acute angle closure
- Primary glaucoma due to combination of mechanisms
- Secondary acute angle closure
- Secondary acute angle closure due to neovascularization
- Secondary acute angle closure due to uveitis
- Secondary angle closure
- Secondary angle closure due to neovascularization
- Secondary angle closure due to uveitis
- Secondary angle closure glaucoma of left eye
- Secondary angle-closure glaucoma
- Secondary angle-closure glaucoma of right eye
Clinical Classification
Clinical Classifications group individual ICD-10-CM diagnosis codes into broader, clinically meaningful categories. These categories help simplify complex data by organizing related conditions under common clinical themes.
They are especially useful for data analysis, reporting, and clinical decision-making. Even when diagnosis codes differ, similar conditions can be grouped together based on their clinical relevance. Each category is assigned a unique CCSR code that represents a specific clinical concept, often tied to a body system or medical specialty.
Glaucoma
CCSR Code: EYE003
Inpatient Default: X - Not applicable.
Outpatient Default: X - Not applicable.
Tabular List of Diseases and Injuries
The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.
Code First
Code FirstCertain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.
- 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
Type 1 Excludes
Type 1 ExcludesA type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Code Edits
The Medicare Code Editor (MCE) detects errors and inconsistencies in ICD-10-CM diagnosis coding that can affect Medicare claim validity. These Medicare code edits help medical coders and billing professionals determine when a diagnosis code is not appropriate as a principal diagnosis, does not meet coverage criteria. Use this list to verify whether a code is valid for Medicare billing and to avoid claim rejections or denials due to diagnosis coding issues.
Manifestation diagnoses
Manifestation codes describe the manifestation of an underlying disease, not the disease itself, and therefore should not be used as a principal diagnosis.
Convert H42 to ICD-9-CM
Below are the ICD-9 codes that most closely match this ICD-10 code, based on the General Equivalence Mappings (GEMs). This ICD-10 to ICD-9 crosswalk tool is helpful for coders who need to reference legacy diagnosis codes for audits, historical claims, or approximate code comparisons.
Glaucoma w systemic synd
ICD-9-CM: 365.44
Approximate Flag - The approximate mapping means this ICD-10 code does not have an exact ICD-9 equivalent. The matched code is the closest available option, but it may not fully capture the original diagnosis or clinical intent.
Patient Education
Glaucoma
Glaucoma is a group of diseases that can damage the eye's optic nerve. It is a leading cause of blindness in the United States. It usually happens when the fluid pressure inside the eyes slowly rises, damaging the optic nerve. Often there are no symptoms at first. Without treatment, people with glaucoma will slowly lose their peripheral, or side vision. They seem to be looking through a tunnel. Over time, straight-ahead vision may decrease until no vision remains.
A comprehensive eye exam can tell if you have glaucoma. People at risk should get eye exams at least every two years. They include:
- African Americans over age 40
- People over age 60, especially Mexican Americans
- People with a family history of glaucoma
There is no cure, but glaucoma can usually be controlled. Early treatment can help protect your eyes against vision loss. Treatments usually include prescription eyedrops and/or surgery.
NIH: National Eye Institute
[Learn More in MedlinePlus]
Code History
- FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
- FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
- FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
- FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
- FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
- FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
- FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
- FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
- FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.
Footnotes
[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:
- The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
- The condition places limitations on self-care, independent living, and social interactions.