2026 ICD-10-CM Diagnosis Code H16.299Other keratoconjunctivitis, unspecified eye

ICD-10-CM Codes›H00–H59›H15-H22›H16

ICD-10-CM H16.299
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

H16.299 is a billable ICD-10-CM diagnosis code for other keratoconjunctivitis, unspecified eye. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 124 through 125. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Cornea and external disease.

Code Identity

ICD-10-CM Code
H16.299
Billable Status
Yes — Valid for Submission
Code Describes
Other keratoconjunctivitis, unspecified eye
Short Description
Other keratoconjunctivitis, unspecified eye
Same as the full description in the CMS dataset.
Parent Code
H16.29
Other keratoconjunctivitis

Code Classification

ChapterH00–H59Diseases of the eye and adnexa
SectionH15-H22Disorders of sclera, cornea, iris and ciliary body
CategoryH16Keratitis
This CodeH16.299Other keratoconjunctivitis, unspecified eye

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Atopic conjunctivitis
  • Atopic keratoconjunctivitis
  • Conjunctivitis caused by drug
  • Dendriform epithelial keratoconjunctivitis
  • Diffuse stromal keratoconjunctivitis
  • Disease caused by Moraxella
  • Drug-induced disorder of cornea
  • Drug-induced keratoconjunctivitis
  • Keratoconjunctivitis caused by Moraxella bovis
  • Keratoconjunctivitis nodosa
  • Microsporidia keratoconjunctivitis
  • Parasitic conjunctivitis
  • Parasitic keratitis
  • Protozoal conjunctivitis
  • Superior limbic keratoconjunctivitis
  • Toxic keratoconjunctivitis
  • Vernal conjunctivitis
  • Vernal keratoconjunctivitis

Clinical ClassificationClinical

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

CCSR EYE001
Cornea and external disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Vernal Conjunctivitis

    inflammation of the cornea that is seasonal in nature.

Patient EducationClinical

Corneal Disorders

Your cornea is the outermost layer of your eye. It is clear and shaped like a dome. The cornea helps to shield the rest of the eye from germs, dust, and other harmful matter. It also helps your eye to focus. If you wear contact lenses, they float on top of your corneas.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert H16.299 to ICD-9-CMHistory

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

ICD-9-CM
370.44 Keratitis in exanthema
Approximate The match is approximate rather than exact.
ICD-9-CM
370.49 Keratoconjunctivitis NEC
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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About H16.299Overview

Is H16.299 (Other keratoconjunctivitis) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other keratoconjunctivitis, unspecified eye on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does H16.299 group to?

When other keratoconjunctivitis, unspecified eye is the principal diagnosis on an inpatient stay, it groups to MS-DRG 124, 125, with relative weights from 0.7678 to 1.3231 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of H16.299?

Under the General Equivalence Mappings, other keratoconjunctivitis, unspecified eye converts to ICD-9-CM 370.44 (keratitis in exanthema) and 370.49 (keratoconjunctivitis NEC). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.