C7A.1 Malignant poorly differentiated neuroendocrine tumors

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

Applicable to

• Malignant poorly differentiated neuroendocrine tumor NOS
• Malignant poorly differentiated neuroendocrine carcinoma, any site
• High grade neuroendocrine carcinoma, any site

Applies from C7A Malignant neuroendocrine tumors

Excludes2 (not included here)

• malignant pancreatic islet cell tumors (C25.4)
• Merkel cell carcinoma (C4A.-)

Use additional code

• code to identify any associated endocrine syndrome, such as:
• carcinoid syndrome (E34.00)

Code also

• any associated multiple endocrine neoplasia [MEN] syndromes (E31.2-)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 21 — Lymphoma and Other Cancers
• 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) 826-828 in MDC 17.

Approximate ICD-9-CM (GEMs)

• 209.30 Malignant poorly differentiated neuroendocrine carcinoma, any site (approximate)

Code annotations containing back-references to C7A.1

Back-references to C7A

• Type 1 Excludes: C75 Malignant neoplasm of other endocrine glands and related structures ("malignant neuroendocrine tumors (C7A.-)")
• Code Also: E34.0 Carcinoid syndrome ("primary neuroendocrine tumors (C7A.-)")

Diagnosis Index entries for C7A.1

• Carcinoma (malignant) › neuroendocrine › high grade, any site
• Carcinoma (malignant) › neuroendocrine › poorly differentiated, any site
• Tumor › neuroendocrine › malignant poorly differentiated

Nearby codes

• C7A.093 Malignant carcinoid tumor of the kidney
• C7A.094 Malignant carcinoid tumor of the foregut, unspecified
• C7A.095 Malignant carcinoid tumor of the midgut, unspecified
• C7A.096 Malignant carcinoid tumor of the hindgut, unspecified
• C7A.098 Malignant carcinoid tumors of other sites
• C7A.1 Malignant poorly differentiated neuroendocrine tumors (this code)
• C7A.8 Other malignant neuroendocrine tumors