D21
Non-Billable (Header)Other benign neoplasms of connective and other soft tissue
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
What This Code Means
D21 is the ICD-10-CM diagnosis code for other benign neoplasms of connective and other soft tissue. D21 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering benign neoplasms, except benign neuroendocrine tumors (d10-d36).
Header codes like D21 cannot be reported on claims directly — they organize child codes that share clinical context but the actual diagnosis must be coded to the highest level of specificity supported by the documentation. Coders should look at D21's child codes and select the one that matches the patient's documented presentation, since payers reject header codes submitted as the primary diagnosis. For risk adjustment workflows, header codes never contribute to a Medicare Advantage member's RAF score on their own; only billable child codes that happen to map to a payment HCC affect risk-adjusted plan payments.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for D21 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Includes
- benign neoplasm of blood vessel
- benign neoplasm of bursa
- benign neoplasm of cartilage
- benign neoplasm of fascia
- benign neoplasm of fat
- benign neoplasm of ligament, except uterine
- benign neoplasm of lymphatic channel
- benign neoplasm of muscle
- benign neoplasm of synovia
- benign neoplasm of tendon (sheath)
- benign stromal tumors
Excludes 1 — Do NOT code together
- benign neoplasm of articular cartilage (D16.-)
- benign neoplasm of cartilage of larynx (D14.1)
- benign neoplasm of cartilage of nose (D14.0)
- benign neoplasm of connective tissue of breast (D24.-)
- benign neoplasm of peripheral nerves and autonomic nervous system (D36.1-)
- benign neoplasm of peritoneum (D20.1)
- benign neoplasm of retroperitoneum (D20.0)
- benign neoplasm of uterine ligament, any (D28.2)
- benign neoplasm of vascular tissue (D18.-)
- hemangioma (D18.0-)
- lipomatous neoplasm (D17.-)
- lymphangioma (D18.1)
- uterine leiomyoma (D25.-)