ICD-10 Code H50.642 – Lateral rectus muscle entrapment, left eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H50.642 – Lateral rectus muscle entrapment, left eye
What it is
H50.642 identifies entrapment of the lateral rectus muscle in the left eye. Use this code when documentation shows the muscle is mechanically trapped, usually after trauma or orbital injury.
Clinical signs
Clinical features vary; refer to documentation. Typical findings may include restricted eye movement, diplopia, pain with gaze, or evidence of orbital fracture with muscle involvement.
When to use this code
Use H50.642 when the provider documents left lateral rectus muscle entrapment as the diagnosis. It may appear in ophthalmology, emergency, or trauma records after imaging or surgical assessment confirms the finding.
Code it when the record clearly links the entrapment to the left eye and the lateral rectus muscle. If the note only mentions diplopia, orbital fracture, or eye pain without entrapment, check documentation.
Do not use for
Do not use this code for nonspecific strabismus, muscle palsy, or orbital fracture without documented entrapment. Do not assume laterality or muscle involvement when the record is unclear.
Coding tip
Confirm both the exact muscle and the left-eye laterality in the provider note before assigning H50.642.