ICD-10 Code D21 – Other benign neoplasms of connective and other soft tissue (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D21 – Other benign neoplasms of connective and other soft tissue
What it is
D21 identifies a benign, noncancerous tumor arising from connective tissue or other soft tissue. Use it when the record documents a soft tissue neoplasm that is not specified as malignant or in another more specific category.
Clinical signs
These lesions often appear as a localized, slow-growing mass or lump. Clinical features vary; refer to documentation, and confirm the benign nature and tissue of origin when available.
When to use this code
Use D21 when the provider documents a benign neoplasm of connective tissue or soft tissue and does not name a more specific site or subtype. It is appropriate for pathology-confirmed benign soft tissue tumors and for documented benign masses coded to this category. If the note specifies a different benign tumor code, use that instead.
Do not use for
Do not use D21 for malignant soft tissue tumors, uncertain behavior, or lesions described as cysts, inflammatory masses, or traumatic swellings. Check documentation if the diagnosis is not clearly a benign neoplasm.
Coding tip
Code from the most specific pathology or provider diagnosis, and verify the exact soft tissue site before assigning D21.