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H18.509 ICD-10-CM Code: Unspecified hereditary corneal dystrophies, unspecified eye

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Inpatient Payment Groups (MS-DRG)

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43.0, Appendix B.

  • MS-DRG 124 — OTHER DISORDERS OF THE EYE WITH MCC OR THROMBOLYTIC AGENT (MDC 02)
  • MS-DRG 125 — OTHER DISORDERS OF THE EYE WITHOUT MCC (MDC 02)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Official Registry Overview & Definition

Unspecified hereditary corneal dystrophies, unspecified eye is a billable ICD-10-CM diagnosis code (H18.509).

Change history

  • FY2021 — 2020-10-01
    Added to the code set
    Unspecified hereditary corneal dystrophies, unspecified eye
    FY2021 changes

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim.

Relationships & Classification

Potential MS-DRG Relationships (FY2026)

Not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity.

Named in the grouper logic of 2 MS-DRGs: DRG 124 (MDC 02), DRG 125 (MDC 02).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):EYE001 — Cornea and external disease (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Cornea and external disease).

+809 more

Contextual Map

Every relationship of H18.509 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Hierarchy

  • H00-H59 — Chapter 7: Diseases of the Eye and Adnexa (H00-H59) (H00-H59) [Hierarchy]
  • H15-H22 — Disorders of sclera, cornea, iris and ciliary body [Hierarchy]

Clinical classification (CCSR)

  • EYE001 — Cornea and external disease [CCSR]

Potential MS-DRG

  • DRG 124 — OTHER DISORDERS OF THE EYE WITH MCC OR THROMBOLYTIC AGENT [MS-DRG]: “OTHER DISORDERS OF THE EYE WITH MCC OR THROMBOLYTIC AGENT (MDC 02)”
  • DRG 125 — OTHER DISORDERS OF THE EYE WITHOUT MCC [MS-DRG]: “OTHER DISORDERS OF THE EYE WITHOUT MCC (MDC 02)”

MDC crossing · procedures (1200)

  • MDC 02 — Diseases and Disorders of the Eye [MDC crossing]: “Diseases and Disorders of the Eye — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs.”
  • 039S0ZX — Drainage of Right Temporal Artery, Open Approach, Diagnostic [Same-MDC procedure]: “Drainage of Right Temporal Artery, Open Approach, Diagnostic — grouped in MDC 02, the procedure side of this code's crossing.” · check together
  • 039S4ZX — Drainage of Right Temporal Artery, Percutaneous Endoscopic Approach, Diagnostic [Same-MDC procedure]: “Drainage of Right Temporal Artery, Percutaneous Endoscopic Approach, Diagnostic — grouped in MDC 02, the procedure side of this code's crossing.” · check together
  • 039T0ZX — Drainage of Left Temporal Artery, Open Approach, Diagnostic [Same-MDC procedure]: “Drainage of Left Temporal Artery, Open Approach, Diagnostic — grouped in MDC 02, the procedure side of this code's crossing.” · check together
  • 039T4ZX — Drainage of Left Temporal Artery, Percutaneous Endoscopic Approach, Diagnostic [Same-MDC procedure]: “Drainage of Left Temporal Artery, Percutaneous Endoscopic Approach, Diagnostic — grouped in MDC 02, the procedure side of this code's crossing.” · check together
  • 03BS0ZX — Excision of Right Temporal Artery, Open Approach, Diagnostic [Same-MDC procedure]: “Excision of Right Temporal Artery, Open Approach, Diagnostic — grouped in MDC 02, the procedure side of this code's crossing.” · check together
  • and 1195 more

Nearest codes (40)

  • H18 — Other disorders of cornea [Sibling]
  • H18.441 — Keratomalacia, right eye [Sibling]
  • H18.442 — Keratomalacia, left eye [Sibling]
  • H18.443 — Keratomalacia, bilateral [Sibling]
  • H18.449 — Keratomalacia, unspecified eye [Sibling]
  • H18.45 — Nodular corneal degeneration [Sibling]
  • H18.451 — Nodular corneal degeneration, right eye [Sibling]
  • H18.452 — Nodular corneal degeneration, left eye [Sibling]
  • and 32 more

Change history

  • FY2021 — Added to the code set [Change history]

Nearest Codes in This Family

Official ICD-10-CM classifications closest to H18.509 in its code family, with their registry titles.

  • H18.5 — Hereditary corneal dystrophies
  • H18.50 — Unspecified hereditary corneal dystrophies
  • H18.501 — Unspecified hereditary corneal dystrophies, right eye
  • H18.502 — Unspecified hereditary corneal dystrophies, left eye
  • H18.503 — Unspecified hereditary corneal dystrophies, bilateral
  • H18.51 — Endothelial corneal dystrophy
  • H18.511 — Endothelial corneal dystrophy, right eye
  • H18.512 — Endothelial corneal dystrophy, left eye
  • H18.513 — Endothelial corneal dystrophy, bilateral
  • H18.519 — Endothelial corneal dystrophy, unspecified eye

View all codes in the H18 family