ICD-10 Code H50.659 – Medial rectus muscle entrapment, unspecified eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H50.659 – Medial rectus muscle entrapment, unspecified eye
What it is
This code identifies entrapment of the medial rectus muscle in an unspecified eye. It indicates restricted movement caused by the muscle being caught or trapped, rather than a general eye alignment disorder.
Clinical signs
Typical findings include limited horizontal eye movement, diplopia, or pain with attempted gaze. Clinical features vary; refer to documentation.
When to use this code
Use this code when the clinician documents medial rectus muscle entrapment and does not specify the affected eye. It is appropriate for records describing mechanical restriction of the medial rectus, including trauma-related or post-procedural cases if the diagnosis is clearly stated. Check documentation if laterality is available.
Do not use for
Do not use this code for nonspecific strabismus, isolated diplopia, or eye pain without documented entrapment. If the record identifies the right or left eye, use the laterality-specific code instead.
Coding tip
Confirm that the note names medial rectus entrapment, not just restricted eye movement, before assigning H50.659.