H16.399 Other interstitial and deep keratitis, unspecified eye

The ICD-10-CM code for Other interstitial and deep keratitis, unspecified eye is H16.399 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

7: Diseases of the eye and adnexa (H00-H59)

Section

H15-H22: Disorders of sclera, cornea, iris and ciliary body (H15-H22)

Category H16

163 codes (126 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to H16.399:

• Keratitis (nodular) (nonulcerative) (simple) (zonular) › deep › specified type NEC

U.S. Hospital Utilization

H16.399 appeared in too few sampled U.S. inpatient stays in 2018 to report a national estimate (AHRQ suppresses counts of 10 or fewer) — a rare inpatient diagnosis.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

Glaucoma (TOC entry)

a. Glaucoma .............................................................................................................................. 48

Assigning glaucoma codes (use as many H40 codes as needed)

Assign as many codes from category H40, Glaucoma, as needed to identify the type of glaucoma, the affected eye, and the glaucoma stage.

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)

Cite This Page

Reference H16.399 with the canonical source and edition:

H16.399 — Other interstitial and deep keratitis, unspecified eye. ICD-10 Coding Pro (ICD-10-CM FY2026). https://icd10codingpro.com/codes/H16.399

Canonical URL: https://icd10codingpro.com/codes/H16.399