2027 ICD-10-CM Diagnosis Code H40.9Unspecified glaucoma
ICD-10-CM Codes›H00–H59›H40-H42›H40
- Billable — Valid for Submission
- Chronic Condition
H40.9 is a billable ICD-10-CM diagnosis code for unspecified glaucoma. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 124 through 125. Coders also document this condition as bilateral glaucoma. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Glaucoma.
H40.9 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 244 for payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
H40.9 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model, but it maps to payment categories in the other CMS models shown below.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Bilateral glaucoma
- Glaucoma
- Glaucoma due to diabetes mellitus
- Glaucoma due to type 2 diabetes mellitus
- Glaucoma in endocrine, nutritional and metabolic diseases
- Glaucoma of left eye
- Glaucoma of right eye
- Iatrogenic glaucoma
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to H40.9: its own notes plus those printed at H40 and Chapter 7. A note printed at a category, block or chapter applies to every code under it.
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- diabetes mellitus related eye conditions (E09.3-, E10.3-, E11.3-, E13.3-)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury (trauma) of eye and orbit (S05.-)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
- syphilis related eye disorders (A50.01, A50.3-, A51.43, A52.71)
Notes
General instructions on how these codes are used.
- Use an external cause code following the code for the eye condition, if applicable, to identify the cause of the eye condition
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Glaucoma H40.9
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Glaucoma
an ocular disease, occurring in many forms, having as its primary characteristics an unstable or a sustained increase in the intraocular pressure which the eye cannot withstand without damage to its structure or impairment of its function. the consequences of the increased pressure may be manifested in a variety of symptoms, depending upon type and severity, such as excavation of the optic disk, hardness of the eyeball, corneal anesthesia, reduced visual acuity, seeing of colored halos around lights, disturbed dark adaptation, visual field defects, and headaches. (dictionary of visual science, 4th ed)
Patient EducationClinical
Glaucoma
Glaucoma is a group of diseases that can damage the optic nerve of one, or both, of your eyes. This can result in vision loss. There are different types of glaucoma, but the most common type is open-angle glaucoma. Other less common types include angle-closure glaucoma, and congenital glaucoma.
The full article covers:
- What is glaucoma?
- What causes glaucoma?
- What are the symptoms of glaucoma?
- How is glaucoma diagnosed?
- What are the treatments for glaucoma?
- Can glaucoma be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert H40.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About H40.9Overview
What is the ICD-10 code for unspecified glaucoma?
The ICD-10-CM code for unspecified glaucoma is H40.9 (sometimes written as H409). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is H40.9 (Glaucoma) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report unspecified glaucoma on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does H40.9 group to?
When unspecified glaucoma is the principal diagnosis on an inpatient stay, it groups to MS-DRG 125, 124, with relative weights from 0.7699 to 1.2470 depending on complications. Higher weights mean higher Medicare reimbursement.
Can H40.9 be reported with a code from H44.51?
Not as a rule. The Excludes1 note at H40, which applies to H40.9, lists "absolute glaucoma (H44.51-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What is the ICD-9 equivalent of H40.9?
Under the General Equivalence Mappings, unspecified glaucoma converts to ICD-9-CM 365.9 (glaucoma NOS). The mapping is a direct match.
Does H40.9 risk-adjust for Medicare Advantage payment?
Not for Medicare Advantage: H40.9 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 244 (Other Non-Acute Glaucoma).
