E24.3 Ectopic ACTH syndrome

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applies from E24 Cushing's syndrome

Excludes1 (never code together)

• congenital adrenal hyperplasia (E25.0)

Risk adjustment (HCC)

• CMS-HCC V22: HCC 23 — Other Significant Endocrine and Metabolic Disorders
• RxHCC V08: HCC 43 — Pituitary, Adrenal Gland, and Other Endocrine and Metabolic Disorders
• ESRD V24: HCC 23

MS-DRG index

Defines the logic of DRG(s) 643-645 in MDC 10.

Approximate ICD-9-CM (GEMs)

• 255.0 Cushing's syndrome (approximate)

Code annotations containing back-references to E24.3

Back-references to E24.3

• Type 1 Excludes: E34.2 Ectopic hormone secretion, not elsewhere classified ("ectopic ACTH syndrome (E24.3)")

Back-references to E24

• Code First: E08 Diabetes mellitus due to underlying condition ("Cushing's syndrome (E24.-)")
• Type 1 Excludes: E22 Hyperfunction of pituitary gland ("Cushing's syndrome (E24.-)")
• Type 1 Excludes: E27.0 Other adrenocortical overactivity ("Cushing's syndrome (E24.-)")
• Code First: G63 Polyneuropathy in diseases classified elsewhere ("endocrine disease, except diabetes (E00-E07, E15-E16, E20-E34)")

Diagnosis Index entries for E24.3

• ACTH ectopic syndrome
• Ectopic, ectopia (congenital) › ACTH syndrome
• Syndrome › Cushing's › due to › ectopic ACTH
• Syndrome › ectopic ACTH

Nearby codes

• E24 Cushing's syndrome
• E24.0 Pituitary-dependent Cushing's disease
• E24.1 Nelson's syndrome
• E24.2 Drug-induced Cushing's syndrome
• E24.3 Ectopic ACTH syndrome (this code)
• E24.4 Alcohol-induced pseudo-Cushing's syndrome
• E24.8 Other Cushing's syndrome
• E24.9 Cushing's syndrome, unspecified