C49.A0 Gastrointestinal stromal tumor, unspecified site

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

Applies from C49 Malignant neoplasm of other connective and soft tissue

Includes

• malignant neoplasm of blood vessel
• malignant neoplasm of bursa
• malignant neoplasm of cartilage
• malignant neoplasm of fascia
• malignant neoplasm of fat
• malignant neoplasm of ligament, except uterine
• malignant neoplasm of lymphatic vessel
• malignant neoplasm of muscle
• malignant neoplasm of synovia
• malignant neoplasm of tendon (sheath)

Excludes1 (never code together)

• malignant neoplasm of cartilage (of):
• articular (C40-C41)
• larynx (C32.3)
• nose (C30.0)
• malignant neoplasm of connective tissue of breast (C50.-)

Excludes2 (not included here)

• Kaposi's sarcoma of soft tissue (C46.1)
• malignant neoplasm of heart (C38.0)
• malignant neoplasm of peripheral nerves and autonomic nervous system (C47.-)
• malignant neoplasm of peritoneum (C48.2)
• malignant neoplasm of retroperitoneum (C48.0)
• malignant neoplasm of uterine ligament (C57.3)
• mesothelioma (C45.-)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 23 — Prostate, Breast, and Other Cancers and Tumors
• CMS-HCC V22: HCC 10 — Lymphoma and Other Cancers
• RxHCC V08: HCC 20 — Lung, Kidney, and Other Cancers; Secondary Cancer of Lymph Nodes and Other Sites
• ESRD V24: HCC 10

MS-DRG index

Defines the logic of DRG(s) 374-376 in MDC 06.

Approximate ICD-9-CM (GEMs)

• 171.5 Malignant neoplasm of connective and other soft tissue of abdomen (approximate)

Code annotations containing back-references to C49.A0

Back-references to C49

• Code First: M63 Disorders of muscle in diseases classified elsewhere ("neoplasm (C49.-, C79.89, D21.-, D48.1-)")

Diagnosis Index entries for C49.A0

• Tumor › stromal › gastrointestinal › malignant

Nearby codes

• C49.5 Malignant neoplasm of connective and soft tissue of pelvis
• C49.6 Malignant neoplasm of connective and soft tissue of trunk, unspecified
• C49.8 Malignant neoplasm of overlapping sites of connective and soft tissue
• C49.9 Malignant neoplasm of connective and soft tissue, unspecified
• C49.A Gastrointestinal stromal tumor
• C49.A0 Gastrointestinal stromal tumor, unspecified site (this code)
• C49.A1 Gastrointestinal stromal tumor of esophagus
• C49.A2 Gastrointestinal stromal tumor of stomach
• C49.A3 Gastrointestinal stromal tumor of small intestine
• C49.A4 Gastrointestinal stromal tumor of large intestine
• C49.A5 Gastrointestinal stromal tumor of rectum