2027 ICD-10-CM Diagnosis Code H40.031Anatomical narrow angle, right eye

ICD-10-CM Codes›H00–H59›H40-H42›H40

ICD-10-CM H40.031
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

H40.031 is a billable ICD-10-CM diagnosis code for anatomical narrow angle, right eye. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Glaucoma.

Code Identity

ICD-10-CM Code
H40.031
Billable Status
Yes — Valid for Submission
Code Describes
Anatomical narrow angle, right eye
Short Description
Anatomical narrow angle, right eye
Same as the full description in the CMS dataset.
Parent Code
H40.03
Anatomical narrow angle

Code Classification

ChapterH00–H59Diseases of the eye and adnexa
SectionH40-H42Glaucoma
CategoryH40Glaucoma
This CodeH40.031Anatomical narrow angle, right eye

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acute angle closure due to anterior chamber angle anomaly
  • Acute angle closure due to intraocular neoplasm
  • Acute angle closure of right eye
  • Acute angle closure of right eye caused by drug
  • Acute angle closure of right eye due to congenital malformation of angle of anterior chamber of right eye
  • Acute angle closure of right eye due to intraocular neoplasm
  • Acute angle closure of right eye due to neovascularization
  • Acute angle closure of right eye due to uveitis
  • Angle closure of right eye caused by drug
  • Angle closure of right eye due to congenital malformation of angle of anterior chamber of right eye
  • Angle closure of right eye due to intraocular neoplasm
  • Angle closure of right eye due to iridocorneal endothelial syndrome
  • Angle closure of right eye due to neovascularization
  • Angle closure of right eye due to uveitis
  • Drug-induced acute angle closure
  • Narrow angle of anterior chamber of right eye
  • Narrow angle of right eye
  • Phacomorphic secondary acute angle closure
  • Phacomorphic secondary acute angle closure of right eye
  • Postoperative acute angle closure
  • Postoperative acute angle closure of right eye
  • Postoperative angle closure of right eye
  • Primary angle closure suspect
  • Primary angle closure suspect of right eye
  • Secondary acute angle closure due to neovascularization
  • Secondary acute angle closure due to uveitis
  • Secondary acute angle closure of right eye
  • Secondary angle closure due to neovascularization
  • Secondary angle closure due to uveitis
  • Secondary angle closure of right eye
  • Secondary angle-closure - synechial
  • Secondary angle-closure due to iridocorneal endothelial syndrome
  • Secondary angle-closure of right eye - synechial

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to H40.031: 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.

From H40 Glaucoma applies to 252 codes
  • absolute glaucoma (H44.51-)
  • congenital glaucoma (Q15.0)
  • traumatic glaucoma due to birth injury (P15.3)

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.

From Chapter 7 (H00-H59) Diseases of the eye and adnexa applies to 2,677 codes
  • 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.

From Chapter 7 (H00-H59) Diseases of the eye and adnexa applies to 2,677 codes
  • 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.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR EYE003
Glaucoma
Default principal diagnosis: inpatient Yes · outpatient Yes

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 H40.031 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
365.02 Anatomical narrow angle
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About H40.031Overview

What is the ICD-10 code for anatomical narrow angle, right eye?

The ICD-10-CM code for anatomical narrow angle, right eye is H40.031 (sometimes written as H40031). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is H40.031 (Anatomical narrow angle) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report anatomical narrow angle, right eye on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does H40.031 group to?

When anatomical narrow angle, right eye 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 H40.031 be reported with a code from H44.51?

Not as a rule. The Excludes1 note at H40, which applies to H40.031, 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 H40.031?

Under the General Equivalence Mappings, anatomical narrow angle, right eye converts to ICD-9-CM 365.02 (anatomical narrow angle). The mapping is approximate, so confirm the match fits the documentation.