S61.109 Unspecified open wound of unspecified thumb with damage to nail

ICD-10-CM Diagnosis Code S61.109: Unspecified Open Wound of Unspecified Thumb with Damage to Nail

ICD-10-CM code S61.109 designates an unspecified open wound of an unspecified thumb with damage to the nail. The terminology record is active and classifies this diagnosis under the broader parent concept of an unspecified open wound of the thumb with nail damage. General clinical literature notes that nail bed injuries can affect both appearance and function. 1 2

Plain-language overview

Code S61.109 identifies a diagnosis where a patient has an open wound involving the thumb and nail, but the clinical details lack specification regarding the exact nature of the wound or the affected hand. 1

What this code represents

The official display label for S61.109 is Unspecified open wound of unspecified thumb with damage to nail, and the concept's semantic type is classified as Injury or Poisoning. 1

Coding details

In the ICD-10-CM terminology, S61.109 is an active code that has no narrower concepts, meaning it does not branch into more specific subcodes within the current version. 1

The parent concept for S61.109 is S61.10, which represents an unspecified open wound of the thumb with damage to the nail, establishing the direct hierarchical category for this diagnosis. 1

Clinical context

Clinical literature establishes that nail bed injuries can be functionally incapacitating and unaesthetic, as the nail structure helps increase sensory perception in the pulp and assists in picking up small objects. 2

Documentation considerations

The terminology record for S61.109 explicitly labels both the wound and the thumb as unspecified, and a Medicare billing article lists alternative thumb injury codes that explicitly denote laterality and sequela status. 1 3

What the sources add

While the terminology record provides the official code definition and hierarchy, clinical literature adds operational context by explaining the functional importance of the nail bed anatomy in sensory perception and fine motor tasks. 1 2

Coverage and utilization context

A Medicare billing and coding article includes a list of specific thumb and nail injury codes that contain explicit laterality and encounter details, contrasting with the unspecified nature of S61.109. 3 1

Sources

1. ICD-10-CM S61.109 terminology record — National Cancer Institute Enterprise Vocabulary Services; accessed 2026-07-27.
2. Nail bed injuries and deformities of nail — pmc.ncbi.nlm.nih.gov; accessed 2026-07-27.
3. Article - Billing and Coding: Surgical Treatment of Nails (A59028) — cms.gov; accessed 2026-07-27.