ICD-10 Code E24.1 – Nelson’s syndrome (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E24.1 – Nelson’s syndrome
What it is
E24.1 identifies Nelson’s syndrome, a complication that can occur after removal of both adrenal glands in a patient with Cushing disease. It reflects pituitary ACTH overproduction with progressive pituitary enlargement.
Clinical signs
Typical findings include rising ACTH levels, skin hyperpigmentation, and evidence of an enlarging pituitary tumor. Clinical features vary; refer to documentation.
When to use this code
Use E24.1 when the record specifically documents Nelson’s syndrome or post-adrenalectomy ACTH excess due to pituitary disease. Code it when the diagnosis is established, not merely suspected. Check documentation for the relationship to prior adrenal surgery.
Do not use for
Do not use this code for generic Cushing syndrome, adrenal insufficiency, or pituitary adenoma without Nelson’s syndrome documented. If the chart is unclear, check documentation.
Coding tip
Link the code to the documented history of bilateral adrenalectomy and pituitary ACTH excess when present.