2027 ICD-10-CM Diagnosis Code H18.43Other calcerous corneal degeneration

ICD-10-CM Codes›H00–H59›H15-H22›H18

ICD-10-CM H18.43
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

H18.43 is a billable ICD-10-CM diagnosis code for other calcerous corneal degeneration. 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 deposit in corneas. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Cornea and external disease.

Code Identity

ICD-10-CM Code
H18.43
Billable Status
Yes — Valid for Submission
Code Describes
Other calcerous corneal degeneration
Short Description
Other calcerous corneal degeneration
Same as the full description in the CMS dataset.
Parent Code
H18.4
Corneal degeneration

Code Classification

ChapterH00–H59Diseases of the eye and adnexa
SectionH15-H22Disorders of sclera, cornea, iris and ciliary body
CategoryH18Other disorders of cornea
This CodeH18.43Other calcerous corneal degeneration

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bilateral deposit in corneas
  • Calcareous degeneration of cornea
  • Calcareous degeneration of cornea of bilateral eyes
  • Calcareous degeneration of cornea of left eye
  • Calcareous degeneration of cornea of right eye
  • Corneal facet

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to H18.43: its own notes plus those printed at H18.4 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 H18.4 Corneal degeneration applies to 23 codes

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.

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

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

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 H18.43 to ICD-9-CMHistory

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

ICD-9-CM
371.44 Calcer cornea degen NEC
Exact Match The mapping is direct, with no qualifiers.

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 H18.43Overview

What is the ICD-10 code for other calcerous corneal degeneration?

The ICD-10-CM code for other calcerous corneal degeneration is H18.43 (sometimes written as H1843). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is H18.43 (Corneal degeneration) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other calcerous corneal degeneration on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does H18.43 group to?

When other calcerous corneal degeneration 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 H18.43 be reported with a code from H16.0?

Not as a rule. The Excludes1 note at H18.4, which applies to H18.43, lists "Mooren's ulcer (H16.0-)". 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 H18.43?

Under the General Equivalence Mappings, other calcerous corneal degeneration converts to ICD-9-CM 371.44 (calcer cornea degen NEC). The mapping is a direct match.