H17.9 Unspecified corneal scar and opacity

ICD-10-CM Code H17.9: Unspecified Corneal Scar and Opacity

ICD-10-CM code H17.9 represents an unspecified corneal scar and opacity, utilized when clinical documentation lacks detail on the specific type or location of the condition. Corneal opacity arises from various etiologies, including trauma and infections. If documentation specifies laterality or a distinct subtype, more specific codes within the H17 category are used instead of this unspecified option. 1 3

Plain-language overview

Corneal opacity is a clinical condition arising from various etiologies, including trauma, corneal edema, corneal dystrophies, corneal degenerations, trachoma, and other corneal infections. If left untreated, conditions like corneal foreign bodies can lead to corneal scarring and visual impairment. 1 2

What this code represents

H17.9 is a valid, billable ICD-10-CM diagnosis code for 2026, classified under Diseases of the eye and adnexa (H00-H59). It describes an unspecified corneal scar and opacity, used when documentation does not specify the type or location of the scar. 3

Coding details

Coders use H17.9 only when documentation does not support a more specific subcode such as H17.0, H17.1, or H17.8. A corneal scar in the right eye or left eye is not coded to H17.9 once laterality is recorded in the medical record. 3

The ICD-10-CM code tree includes H17.9 alongside other specified corneal scars and opacities, such as H17.813 for minor opacity of the cornea, bilateral, and H17.823 for peripheral opacity of the cornea, bilateral. The approximate ICD-9-CM equivalent for H17.9 is 371.00. 3 4

Documentation considerations

Most H17.9 denials trace back to documentation that describes the opacity in enough clinical detail to support a more specific subcode, but the coder selected the unspecified option anyway. If the eye is not documented and no opacity type is recorded, H17.9 remains the correct code. 3

Clinical context

Corneal opacity or infiltration may be present if a foreign body is retained in the eye. If the body fails to eliminate the foreign object or inflammation becomes chronic, corneal stromal scarring and neovascularization may compromise visual acuity. 2

What the sources add

While S3 provides the billing and coding rules for the H17.9 diagnosis, S1 and S2 provide the clinical background regarding the etiologies and physical manifestations of corneal opacities and scarring. S1 examines a surgical intervention for superficial corneal opacity, whereas S2 discusses complications from corneal foreign bodies. 1 2 3

Coverage and utilization context

In cases with residual scarring or stromal opacity, visual rehabilitation options such as phototherapeutic keratectomy or corneal transplantation may be considered. Excimer laser phototherapeutic keratectomy has been used to treat corneal diseases such as scarring, dystrophies, degenerations, and recurrent corneal erosions. 1 2

Sources

1. Treatment of superficial corneal opacities with corneal stromal lenticule obtained through SMILE surgery — pmc.ncbi.nlm.nih.gov; accessed 2026-07-26.
2. Bookshelf — ncbi.nlm.nih.gov; accessed 2026-07-26.
3. ICD-10 code H17.9: corneal scar and opacity (2026) — pabau.com; accessed 2026-07-26.
4. ICD-10-CM 2024 | H17.8 - Other corneal scars and opacities — unboundmedicine.com; accessed 2026-07-26.