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D21 ICD-10-CM Code: Other benign neoplasms of connective and other soft tissue

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FY 2026 Apr update / Neoplasms (C00-D49) / Benign neoplasms, except benign neuroendocrine tumors (D10-D36)

D21

Header CodeICD-10-CMOfficial ICD-10-CMCodebook guidance

Other benign neoplasms of connective and other soft tissue

Other benign neoplasms of connective and other soft tissue

CMS-HCC V28

N/A

Not mapped

CMS-HCC V24

N/A

Not mapped

ACA/HHS

N/A

Not mapped

ESRD/PACE

N/A

Not mapped

RXHCC

N/A

Not mapped

Code Book Path

Official
D2Benign neoplasms, except benign neuroendocrine tumors (D10-D36)
D21Other benign neoplasms of connective and other soft tissue

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for D21 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for D21 in this effective period.

Related Child Codes

Official
D21.0Benign neoplasm of connective and other soft tissue of head, face and neck
D21.1Benign neoplasm of connective and other soft tissue of upper limb, including shoulder
D21.2Benign neoplasm of connective and other soft tissue of lower limb, including hip
D21.3Benign neoplasm of connective and other soft tissue of thorax
D21.4Benign neoplasm of connective and other soft tissue of abdomen

Includes

Official
  • benign neoplasm of blood vessel
  • benign neoplasm of bursa
  • benign neoplasm of cartilage
  • benign neoplasm of fascia
  • benign neoplasm of fat

Excludes 1

Official
  • 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-)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for D21 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for D21 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for D21 in this effective period.

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Coder workflow notes

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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.-)

Child Codes

Code Hierarchy

D21Other benign neoplasms of connective and other soft tissue
D21Other benign neoplasms of connective and other soft tissue

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