S46.112A Strain of muscle, fascia and tendon of long head of biceps, left arm, initial encounter

ICD-10-CM S46.112A: Strain of muscle, fascia and tendon of long head of biceps, left arm, initial encounter

ICD-10-CM code S46.112A identifies an initial encounter for a strain affecting the muscle, fascia, and tendon of the left arm's long head of the biceps. The terminology record classifies this concept as an injury or poisoning. General clinical literature describes the long head of the biceps tendon as a structure spanning from the shoulder to the forearm. 1 2

Plain-language overview

This diagnosis code represents an injury event involving a strain to the left arm's long head of the biceps, specifically noting that this is the initial encounter for medical care. 1

What this code represents

The terminology record assigns this concept the semantic type of Injury or Poisoning and maintains an active record status for the specified left arm biceps strain. 1

Within the coding hierarchy, this specific initial encounter code is a narrower concept derived from the parent code S46.112 for a left arm long head biceps strain. 1

Clinical context

Anatomical literature establishes that the long head of the biceps brachii tendon originates at the shoulder's supraglenoid tubercle and superior glenoid labrum before joining the short head. 2

Clinical literature describes the long head of the biceps tendon pathologies as spanning a spectrum from acute tendinitis to chronic degenerative tendinopathy and spontaneous rupture. 2

Coding details

The code S46.112A is distinct from S46.112D, which represents a subsequent encounter for the same left arm long head biceps strain, and from S46.111A, the right arm strain. 4

Documentation considerations

The official terminology record publishes an abbreviated description for this concept as the strain of musc, fasc, and tend of the long head of the biceps, left arm, init. 1

Coverage and utilization context

A Medicare billing and coding article includes S46.112A within a list of diagnosis codes associated with tendon, ligament, and ganglion cyst injection procedures. 3

What the sources add

While the official terminology record defines the code's structural meaning, the Medicare article provides operational context by placing the code within a specific billing scenario for tendon injections. 1 3

Sources

1. ICD-10-CM S46.112A terminology record — National Cancer Institute Enterprise Vocabulary Services; accessed 2026-07-27.
2. Bookshelf — ncbi.nlm.nih.gov; accessed 2026-07-27.
3. Article - Billing and Coding: Injections - Tendon, Ligament, Ganglion Cyst, Tunnel Syndromes and Morton's Neuroma (A57079) — cms.gov; accessed 2026-07-27.
4. ICD-10-CM 2024 | S46 - Injury of muscle, fascia and tendon at shoulder and upper arm level — unboundmedicine.com; accessed 2026-07-27.