2026 ICD-10-CM Diagnosis Code H16Keratitis

ICD-10-CM Codes›H00–H59›H15-H22›H16

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

H16 is a non-billable ICD-10-CM category code for keratitis, so it cannot be submitted on claims. Use a more specific code from this category instead, such as H16.001, H16.002, H16.003, and H16.009.

Code Identity

ICD-10-CM Code
H16
Billable Status
No — Non-Billable Category
Code Describes
Keratitis
Chapter
H15-H22
Disorders of sclera, cornea, iris and ciliary body

Code Classification

ChapterH00–H59Diseases of the eye and adnexa
SectionH15-H22Disorders of sclera, cornea, iris and ciliary body
CategoryH16Keratitis
This CodeH16Keratitis

Specific Coding for KeratitisOverview

Non-specific codes like H16 require more characters. Use one of these billable codes instead:

  • H16.0 for Corneal ulcer

  • H16.00 for Unspecified corneal ulcer

  • H16.01 for Central corneal ulcer

  • H16.02 for Ring corneal ulcer

  • H16.03 for Corneal ulcer with hypopyon

  • H16.04 for Marginal corneal ulcer

  • H16.05 for Mooren's corneal ulcer

  • H16.06 for Mycotic corneal ulcer

  • H16.07 for Perforated corneal ulcer

  • H16.1 for Other and unspecified superficial keratitis without conjunctivitis

  • H16.10 for Unspecified superficial keratitis

  • H16.11 for Macular keratitis

  • H16.12 for Filamentary keratitis

  • H16.13 for Photokeratitis

  • H16.14 for Punctate keratitis

  • H16.2 for Keratoconjunctivitis

  • H16.20 for Unspecified keratoconjunctivitis

  • H16.21 for Exposure keratoconjunctivitis

  • H16.22 for Keratoconjunctivitis sicca, not specified as Sjogren's

  • H16.23 for Neurotrophic keratoconjunctivitis

  • H16.24 for Ophthalmia nodosa

  • H16.25 for Phlyctenular keratoconjunctivitis

  • H16.26 for Vernal keratoconjunctivitis, with limbar and corneal involvement

  • H16.29 for Other keratoconjunctivitis

  • H16.3 for Interstitial and deep keratitis

  • H16.30 for Unspecified interstitial keratitis

  • H16.31 for Corneal abscess

  • H16.32 for Diffuse interstitial keratitis

  • H16.33 for Sclerosing keratitis

  • H16.39 for Other interstitial and deep keratitis

  • H16.4 for Corneal neovascularization

  • H16.40 for Unspecified corneal neovascularization

  • H16.41 for Ghost vessels (corneal)

  • H16.42 for Pannus (corneal)

  • H16.43 for Localized vascularization of cornea

  • H16.44 for Deep vascularization of cornea

  • Use H16.8 for Other keratitis

  • Use H16.9 for Unspecified keratitis

Clinical InformationClinical

  • Acanthamoeba Keratitis

    infection of the cornea by an ameboid protozoan which may cause corneal ulceration leading to blindness.

  • Corneal Ulcer

    loss of epithelial tissue from the surface of the cornea due to progressive erosion and necrosis of the tissue; usually caused by bacterial, fungal, or viral infection.

  • Keratitis

    inflammation of the cornea.

  • Keratitis, Dendritic

    a form of herpetic keratitis characterized by the formation of small vesicles which break down and coalesce to form recurring dendritic ulcers, characteristically irregular, linear, branching, and ending in knoblike extremities. (dictionary of visual science, 3d ed)

  • Keratitis, Herpetic

    a superficial, epithelial herpesvirus hominis infection of the cornea, characterized by the presence of small vesicles which may break down and coalesce to form dendritic ulcers (keratitis, dendritic). (dictionary of visual science, 3d ed)

  • Grade 3 Keratitis, CTCAE|CTCAE Grade 3 Keratitis (corneal inflammation/corneal ulceration)|Grade 3 Keratitis|Grade 3 Keratitis (corneal inflammation/corneal ulceration)

    symptomatic with marked decrease in visual acuity (best corrected visual acuity worse than 20/40 or more than 3 lines of decreased vision from known baseline, up to 20/200); corneal ulcer; limiting self-care adl or severe impact on age-appropriate normal daily activity (pediatric)

  • Photokeratitis|Arc Welder's Eye|Arc eye|Ultraviolet Keratitis|Ultraviolet Keratitis|Welder's Flash

    injury to the cornea secondary to ultraviolet light.

  • Stromal Keratitis|Stromal keratitis

    a corneal inflammation affecting the stromal layer.

  • Acanthamoeba Keratitis

    keratitis due to infection by acanthamoeba; it is usually associated with soft contact lens wear, particularly overnight wear.

  • Dendritic Keratitis

    infection of the cornea with herpes simplex virus, resulting in branching ulcers of the corneal tissue.

  • Fungal Keratitis

    keratitis caused by fungi.

  • Grade 1 Keratitis, CTCAE|CTCAE Grade 1 Keratitis (corneal inflammation/corneal ulceration)|Grade 1 Keratitis|Grade 1 Keratitis (corneal inflammation/corneal ulceration)

    asymptomatic; clinical or diagnostic observations only; intervention not indicated

  • Grade 2 Keratitis, CTCAE|CTCAE Grade 2 Keratitis (corneal inflammation/corneal ulceration)|Grade 2 Keratitis|Grade 2 Keratitis (corneal inflammation/corneal ulceration)

    symptomatic; moderate decrease in visual acuity (best corrected visual acuity 20/40 and better or 3 lines or less decreased vision from known baseline)

  • Grade 3 Keratitis, CTCAE|CTCAE Grade 3 Keratitis (corneal inflammation/corneal ulceration)|Grade 3 Keratitis|Grade 3 Keratitis (corneal inflammation/corneal ulceration)

    symptomatic with marked decrease in visual acuity (best corrected visual acuity worse than 20/40 or more than 3 lines of decreased vision from known baseline, up to 20/200); corneal ulcer; limiting self care adl

  • Grade 4 Keratitis, CTCAE|CTCAE Grade 4 Keratitis (corneal inflammation/corneal ulceration)|Grade 4 Keratitis|Grade 4 Keratitis (corneal inflammation/corneal ulceration)

    perforation; best corrected visual acuity of 20/200 or worse in the affected eye

  • Infectious Keratitis|Infective Keratitis

    inflammation of the cornea secondary to an infectious process.

  • Keratitis, CTCAE|Keratitis|Keratitis|Keratitis (corneal inflammation/corneal ulceration)

    a disorder characterized by inflammation to the cornea of the eye.

  • PAX6 wt Allele|AN|AN2|Aniridia, Keratitis Gene|D11S812E|MGC17209|MGDA|Paired Box 6 wt Allele|Paired Box Gene 6 (Aniridia, Keratitis) Gene|WAGR

    human pax6 wild-type allele is located in the vicinity of 11p13 and is approximately 29 kb in length. this allele, which encodes paired box protein pax-6, plays a role in the mediation of transcription. mutations in the gene are associated with a number of congenital disorders of the eye.

  • Photokeratitis|Ultraviolet Keratitis|Ultraviolet Keratitis

    injury to the cornea secondary to ultraviolet light.

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.

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 H16Overview

Is H16 (Keratitis) a billable code?

No. This is a category header that groups the codes for keratitis, and headers cannot be submitted on claims. Claims for keratitis need a more specific code from this category, such as H16.001, H16.002, and H16.003.