ICD-10 Code H49.00 – Third [oculomotor] nerve palsy, unspecified eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H49.00 – Third [oculomotor] nerve palsy, unspecified eye
What it is
Use this code for paralysis or weakness of the third cranial nerve when the affected eye is not specified. It describes impaired oculomotor function without documenting laterality.
Clinical signs
Typical findings include ptosis, limited eye movements, and diplopia. The pupil may be involved or spared, and clinical features vary; refer to documentation.
When to use this code
Assign H49.00 when the record states third nerve palsy or oculomotor nerve palsy but does not identify the right or left eye. Use it for confirmed neurologic documentation, exam findings, or specialist assessment that names the palsy without laterality.
If the note later specifies the eye, code the documented side instead. Check documentation when the record mentions related neurologic disease, trauma, or aneurysm but does not clearly confirm the palsy itself.
Do not use for
Do not use this code for a palsy with documented right or left eye laterality. Do not use it for general diplopia or ptosis when third nerve palsy is not stated.
Coding tip
Look for laterality in the assessment, impression, or problem list before selecting H49.00.