E34.00 Carcinoid syndrome, unspecified

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

Applicable to

• Carcinoid disease, unspecified

Applies from E34 Other endocrine disorders

Excludes1 (never code together)

• pseudohypoparathyroidism (E20.1)

Applies from E34.0 Carcinoid syndrome

Code also

• the underlying disorder, such as:
• primary neuroendocrine tumors (C7A.-)
• secondary neuroendocrine tumors (C7B.-)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 17 — Cancer Metastatic to Lung, Liver, Brain, and Other Organs; Acute Myeloid Leukemia Except Promyelocytic
• CMS-HCC V22: HCC 12 — Breast, Prostate, and Other Cancers and Tumors
• RxHCC V08: HCC 22 — Prostate, Breast, Bladder, and Other Cancers and Tumors
• ESRD V24: HCC 12

MS-DRG index

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

Code annotations containing back-references to E34.00

Back-references to E34.00

• Use Additional: C7A Malignant neuroendocrine tumors ("carcinoid syndrome (E34.00)")
• Use Additional: D3A Benign neuroendocrine tumors ("carcinoid syndrome (E34.00)")

Back-references to E34

• Code First: G63 Polyneuropathy in diseases classified elsewhere ("endocrine disease, except diabetes (E00-E07, E15-E16, E20-E34)")

Diagnosis Index entries for E34.00

• Carcinoidosis
• Disease, diseased › carcinoid
• Syndrome › carcinoid
• Syndrome › malignant › carcinoid
• Syndrome › metastatic carcinoid

Nearby codes

• E34 Other endocrine disorders
• E34.0 Carcinoid syndrome
• E34.00 Carcinoid syndrome, unspecified (this code)
• E34.01 Carcinoid heart syndrome
• E34.09 Other carcinoid syndrome
• E34.1 Other hypersecretion of intestinal hormones
• E34.2 Ectopic hormone secretion, not elsewhere classified
• E34.3 Short stature due to endocrine disorder