2026 ICD-10-CM Diagnosis Code D21.3Benign neoplasm of connective and other soft tissue of thorax
ICD-10-CM Codes›C00–D49›D10-D36›D21
- Billable — Valid for Submission
- Not Chronic
D21.3 is a billable ICD-10-CM diagnosis code for benign neoplasm of connective and other soft tissue of thorax. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 564 through 566. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Benign neoplasms.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Benign neoplasm of blood vessel of axilla
- Benign neoplasm of blood vessel of shoulder
- Benign neoplasm of blood vessel of thorax
- Benign neoplasm of blood vessel of upper limb
- Benign neoplasm of diaphragm
- Benign neoplasm of great vessels
- Benign neoplasm of muscle of abdomen
- Benign neoplasm of muscle of thorax
- Benign neoplasm of muscle of trunk
- Benign neoplasm of soft tissue of back of trunk
- Benign neoplasm of soft tissues of axilla
- Benign neoplasm of soft tissues of thorax
- Benign neoplasm soft tissue of thoracic spine
- Fibroma of chest wall
- Neoplasm of blood vessel of axilla
- Neoplasm of blood vessel of shoulder
- Neoplasm of blood vessel of thorax
- Neoplasm of diaphragm
- Neoplasm of great vessels
- Neoplasm of muscle of abdomen
- Neoplasm of muscle of thorax
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Benign neoplasm of axilla
- Benign neoplasm of diaphragm
- Benign neoplasm of great vessels
Type 1 Excludes
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Contraceptive Devices, Female
contraceptive devices used by females.Diaphragm
the musculofibrous partition that separates the thoracic cavity from the abdominal cavity. contraction of the diaphragm increases the volume of the thoracic cavity aiding inhalation.Diaphragmatic Eventration
a congenital abnormality characterized by the elevation of the diaphragm dome. it is the result of a thinned diaphragmatic muscle and injured phrenic nerve, allowing the intra-abdominal viscera to push the diaphragm upward against the lung.Hernia, Diaphragmatic
protrusion of abdominal structures into the thorax as a result of congenital or traumatic defects in the respiratory diaphragm.Hernia, Diaphragmatic, Traumatic
the type of diaphragmatic hernia caused by trauma or injury, usually to the abdomen.Hernias, Diaphragmatic, Congenital
protrusion of abdominal structures into the thorax as a result of embryologic defects in the diaphragm often present in the neonatal period. it can be isolated, syndromic, non-syndromic or be a part of chromosome abnormality. associated pulmonary hypoplasia and pulmonary hypertension can further complicate stabilization and surgical intervention.Inferior Wall Myocardial Infarction
myocardial infarction in which the inferior wall of the heart is involved. it is often caused by occlusion of the right coronary artery.Pelvic Floor
soft tissue formed mainly by the pelvic diaphragm, which is composed of the two levator ani and two coccygeus muscles. the pelvic diaphragm lies just below the pelvic aperture (outlet) and separates the pelvic cavity from the perineum. it extends between the pubic bone anteriorly and the coccyx posteriorly.Peritoneal Stomata
natural openings in the subdiaphragmatic lymphatic plexus in the peritoneum, delimited by adjacent mesothelial cells. peritoneal stomata constitute the principal pathways for the drainage of intraperitoneal contents from the peritoneal cavity to the lymphatic system.Respiratory Paralysis
complete or severe weakness of the muscles of respiration. this condition may be associated with motor neuron diseases; peripheral nerve diseases; neuromuscular junction diseases; spinal cord diseases; injury to the phrenic nerve; and other disorders.
Table of NeoplasmsClinical
Anatomical sites in the Table of Neoplasms that reference this code family.
| Site | Malig. Primary | Malig. Secondary | Ca in situ | Benign | Uncertain | Unspec. |
|---|---|---|---|---|---|---|
| aorta (thoracic) | C49.3 | C79.89 | – | D21.3 | D48.1 | D49.2 |
| connective tissue NEC › axilla | C49.3 | C79.89 | – | D21.3 | D48.1 | D49.2 |
| connective tissue NEC › chest (wall) | C49.3 | C79.89 | – | D21.3 | D48.1 | D49.2 |
| connective tissue NEC › diaphragm | C49.3 | C79.89 | – | D21.3 | D48.1 | D49.2 |
| connective tissue NEC › great vessels NEC | C49.3 | C79.89 | – | D21.3 | D48.1 | D49.2 |
| connective tissue NEC › infraclavicular region | C49.3 | C79.89 | – | D21.3 | D48.1 | D49.2 |
| connective tissue NEC › intrathoracic | C49.3 | C79.89 | – | D21.3 | D48.1 | D49.2 |
| connective tissue NEC › scapular region | C49.3 | C79.89 | – | D21.3 | D48.1 | D49.2 |
| connective tissue NEC › thoracic (duct) (wall) | C49.3 | C79.89 | – | D21.3 | D48.1 | D49.2 |
| connective tissue NEC › thorax | C49.3 | C79.89 | – | D21.3 | D48.1 | D49.2 |
| diaphragm | C49.3 | C79.89 | – | D21.3 | D48.1 | D49.2 |
| great vessels NEC | C49.3 | C79.89 | – | D21.3 | D48.1 | D49.2 |
| thorax, thoracic (cavity) (organs NEC) › duct | C49.3 | C79.89 | – | D21.3 | D48.1 | D49.2 |
| vena cava (abdominal) (inferior) › superior | C49.3 | C79.89 | – | D21.3 | D48.1 | D49.2 |
Patient EducationClinical
Benign Tumors
Tumors are abnormal growths in your body. They can be either benign or malignant. Benign tumors aren't cancer. Malignant ones are. Benign tumors grow only in one place. They cannot spread or invade other parts of your body. Even so, they can be dangerous if they press on vital organs, such as your brain.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert D21.3 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About D21.3Overview
Is D21.3 (Other benign neoplasms of connective and other soft tissue) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report benign neoplasm of connective and other soft tissue of thorax on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does D21.3 group to?
When benign neoplasm of connective and other soft tissue of thorax is the principal diagnosis on an inpatient stay, it groups to MS-DRG 564, 565, 566, with relative weights from 0.7493 to 1.5436 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of D21.3?
Under the General Equivalence Mappings, benign neoplasm of connective and other soft tissue of thorax converts to ICD-9-CM 215.4 (ben neo soft tis thorax). The mapping is a direct match.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
