2026 ICD-10-CM Diagnosis Code C41.9
Malignant neoplasm of bone and articular cartilage, unspecified
- ICD-10-CM Code:
- C41.9
- ICD-10 Code for:
- Malignant neoplasm of bone and articular cartilage, unsp
- Is Billable?
- Yes - Valid for Submission
- Chronic Condition Indicator: [1]
- Chronic
- Code Navigator:
C41.9 is a billable diagnosis code used to specify a medical diagnosis of malignant neoplasm of bone and articular cartilage, unspecified. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2025 through September 30, 2026.
The following anatomical sites found in the Table of Neoplasms reference this diagnosis code given the correct histological behavior: Neoplasm, neoplastic bone (periosteum) ; Neoplasm, neoplastic bone (periosteum) cartilage NEC ; Neoplasm, neoplastic bone (periosteum) cuneiform ; Neoplasm, neoplastic cartilage (articular) (joint) NEC [See Also: Neoplasm, bone] ; Neoplasm, neoplastic joint NEC [See Also: Neoplasm, bone] ; Neoplasm, neoplastic skeleton, skeletal NEC ; etc
Unspecified diagnosis codes like C41.9 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.
Approximate Synonyms
The following list of clinical terms are approximate synonyms, alternative descriptions, or common phrases that might be used by patients, healthcare providers, or medical coders to describe the same condition. These synonyms and related diagnosis terms are often used when searching for an ICD-10 code, especially when the exact medical terminology is unclear. Whether you're looking for lay terms, similar diagnosis names, or common language alternatives, this list can help guide you to the correct ICD-10 classification.
- Carcinoma of bone, connective tissue, skin and breast
- Chondrosarcoma
- Chondrosarcoma of bone
- Clear cell chondrosarcoma
- Conventional osteosarcoma
- Dedifferentiated chondrosarcoma
- Diaphyseal medullary stenosis with bone malignancy
- Disseminated Langerhans cell histiocytosis of bone
- Ewing's sarcoma of bone
- Extraskeletal mesenchymal chondrosarcoma
- Extraskeletal myxoid chondrosarcoma
- High-grade surface osteosarcoma
- Langerhans cell histiocytosis, disseminated
- Large cell Ewing sarcoma of bone
- Local recurrence of malignant neoplasm of bone
- Low-grade central osteosarcoma
- Macrocytosis - no anemia
- Malignant giant cell tumor of bone
- Malignant neoplasm of articular cartilage
- Malignant neoplasm of bone
- Malignant neoplasm of bone, connective tissue, skin and breast
- Malignant neoplasm of bone, connective tissue, skin and breast
- Malignant neoplasm of skeletal system
- Malignant neoplasm of vertebra
- Mesenchymal chondrosarcoma
- Metastatic extraskeletal osteosarcoma
- Metastatic malignant neoplasm to articular cartilage
- Metastatic malignant neoplasm to articular cartilage
- Metastatic malignant neoplasm to articular cartilage
- Metastatic malignant neoplasm to articular cartilage
- Metastatic malignant neoplasm to clavicle
- Metastatic malignant neoplasm to long bone of upper limb
- Metastatic malignant neoplasm to rib
- Metastatic malignant neoplasm to sternum
- Metastatic malignant neoplasm to vertebral column
- Metastatic malignant neoplasm to vertebral column
- Metastatic osteosarcoma to articular cartilage of clavicle
- Metastatic osteosarcoma to articular cartilage of rib
- Metastatic osteosarcoma to articular cartilage of sternum
- Metastatic osteosarcoma to articular cartilage of vertebra
- Metastatic osteosarcoma to bone
- Metastatic osteosarcoma to bone of clavicle
- Metastatic osteosarcoma to bone of head
- Metastatic osteosarcoma to bone of rib
- Metastatic osteosarcoma to bone of sternum
- Metastatic osteosarcoma to bone of vertebra
- Non-anemic red cell disorder
- Osteosarcoma
- Osteosarcoma of articular cartilage of clavicle
- Osteosarcoma of articular cartilage of rib
- Osteosarcoma of articular cartilage of sternum
- Osteosarcoma of articular cartilage of vertebra
- Osteosarcoma of bone
- Osteosarcoma of bone of clavicle
- Osteosarcoma of bone of head
- Osteosarcoma of bone of rib
- Osteosarcoma of bone of upper limb
- Osteosarcoma of bone of vertebra
- Osteosarcoma of sternum
- Osteosarcoma, limb anomalies, erythroid macrocytosis syndrome
- Overlapping malignant neoplasm of bone and articular cartilage
- Parosteal osteosarcoma
- Periosteal chondrosarcoma
- Periosteal osteosarcoma
- Primary chondrosarcoma of articular cartilage
- Primary chondrosarcoma of bone
- Primary Ewing sarcoma of bone
- Primary large cell Ewing sarcoma of bone
- Primary malignant neoplasm of articular cartilage
- Primary malignant neoplasm of bone
- Primary osteosarcoma
- Primary osteosarcoma of bone
- Sarcoma of bone
- Sarcoma of bone and connective tissue
- Sarcoma of clavicle
- Sarcoma of rib
- Sarcoma of sternum
- Sarcoma of vertebra
- Small cell osteosarcoma
- Telangiectatic osteosarcoma
Clinical Classification
Clinical Classifications group individual ICD-10-CM diagnosis codes into broader, clinically meaningful categories. These categories help simplify complex data by organizing related conditions under common clinical themes.
They are especially useful for data analysis, reporting, and clinical decision-making. Even when diagnosis codes differ, similar conditions can be grouped together based on their clinical relevance. Each category is assigned a unique CCSR code that represents a specific clinical concept, often tied to a body system or medical specialty.
Bone cancer
CCSR Code: NEO023
Inpatient Default: Y - Yes, default inpatient assignment for principal diagnosis or first-listed diagnosis.
Outpatient Default: Y - Yes, default outpatient assignment for principal diagnosis or first-listed diagnosis.
Clinical Information
Osteosarcoma
a sarcoma originating in bone-forming cells, affecting the ends of long bones. it is the most common and most malignant of sarcomas of the bones, and occurs chiefly among 10- to 25-year-old youths. (from stedman, 25th ed)Osteosarcoma, Juxtacortical
a form of osteogenic sarcoma of relatively low malignancy, probably arising from the periosteum and initially involving cortical bone and adjacent connective tissue. it occurs in middle-aged as well as young adults and most commonly affects the lower part of the femoral shaft. (stedman, 25th ed)Chondrosarcoma
a slowly growing malignant neoplasm derived from cartilage cells, occurring most frequently in pelvic bones or near the ends of long bones, in middle-aged and old people. most chondrosarcomas arise de novo, but some may develop in a preexisting benign cartilaginous lesion or in patients with enchondromatosis. (stedman, 25th ed)Chondrosarcoma, Clear Cell
a chondrosarcoma of adolescence to old age of the proximal epiphyses of long bones. it has variably clear cytoplasm of the mostly neoplastic chondrocytes with little intervening matrix.Chondrosarcoma, Mesenchymal
a rare aggressive variant of chondrosarcoma, characterized by a biphasic histologic pattern of small compact cells intermixed with islands of cartilaginous matrix. mesenchymal chondrosarcomas have a predilection for flat bones; long tubular bones are rarely affected. they tend to occur in the younger age group and are highly metastatic. (devita jr et al., cancer: principles & practice of oncology, 3d ed, p1456)Enchondromatosis
benign growths of cartilage in the metaphyses of several bones.
Index to Diseases and Injuries References
The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).
- Osteitis - See Also: Osteomyelitis;
Index of External Cause of Injuries
References found for this diagnosis code in the External Cause of Injuries Index:
- Osteitis
- deformans
- in (due to)
- malignant neoplasm of bone (see also, Neoplasm, malignant, by site)
Convert C41.9 to ICD-9-CM
Below are the ICD-9 codes that most closely match this ICD-10 code, based on the General Equivalence Mappings (GEMs). This ICD-10 to ICD-9 crosswalk tool is helpful for coders who need to reference legacy diagnosis codes for audits, historical claims, or approximate code comparisons.
Malig neopl bone NOS
ICD-9-CM: 170.9
Approximate Flag - The approximate mapping means this ICD-10 code does not have an exact ICD-9 equivalent. The matched code is the closest available option, but it may not fully capture the original diagnosis or clinical intent.
Table of Neoplasms
This code is referenced in the table of neoplasms by anatomical site. For each site there are six possible code numbers according to whether the neoplasm in question is malignant, benign, in situ, of uncertain behavior, or of unspecified nature. The description of the neoplasm will often indicate which of the six columns is appropriate.
Where such descriptors are not present, the remainder of the Index should be consulted where guidance is given to the appropriate column for each morphological (histological) variety listed. However, the guidance in the Index can be overridden if one of the descriptors mentioned above is present.
| Neoplasm, neoplastic | Malignant Primary |
Malignant Secondary |
CaInSitu | Benign | Uncertain Behavior |
Unspecified Behavior |
|---|---|---|---|---|---|---|
| »Neoplasm, neoplastic »bone (periosteum) | C41.9 | C79.51 | D16.9 | D48.0 | D49.2 | |
| »Neoplasm, neoplastic »bone (periosteum) »cartilage NEC | C41.9 | C79.51 | D16.9 | D48.0 | D49.2 | |
| »Neoplasm, neoplastic »bone (periosteum) »cuneiform | C41.9 | C79.51 | D16.9 | D48.0 | D49.2 | |
| »Neoplasm, neoplastic »cartilage (articular) (joint) NEC [See Also: Neoplasm, bone] | C41.9 | C79.51 | D16.9 | D48.0 | D49.2 | |
| »Neoplasm, neoplastic »joint NEC [See Also: Neoplasm, bone] | C41.9 | C79.51 | D16.9 | D48.0 | D49.2 | |
| »Neoplasm, neoplastic »skeleton, skeletal NEC | C41.9 | C79.51 | D16.9 | D48.0 | D49.2 |
Patient Education
Cancer
What is cancer?
Cancer is not just one disease but many diseases. Cancer begins in your cells, which are the building blocks of your body. Usually, your body forms new cells as needed, replacing old cells that die. Sometimes this process goes wrong. New cells grow even when you don't need them, and old cells don't die when they should. These extra cells can form a mass called a tumor.
Tumors can be benign or malignant. Benign tumors aren't cancer, while malignant ones are. Cells from malignant tumors can invade nearby tissues. They can also break away and spread to other parts of your body. The spread of cancer from one part of the body to another is called metastasis. Symptoms and treatment depend on the type of cancer and how advanced it is.
What are the types of cancer?
There are more than 100 different types of cancer. Cancer can start almost anywhere in your body. Most cancers are named for where they start. For example, lung cancer starts in the lung, and breast cancer starts in the breast.
Cancer may also be described by the type of cell that formed it, such as sarcoma if cancer begins in your bone and soft tissue. Carcinoma is the most common type of cancer. It is formed by epithelial cells, the cells that cover the inside and outside surfaces of your body.
How does cancer develop?
Cancer is a genetic disease. That means changes in your genes cause it. Changes in your genes are also called gene variants or mutations. Genes are parts of DNA in your cells that you inherit from your parents. However, only some cancers are caused by genes passed down from your parents.
Genetic changes can occur to your genes over your lifetime that affect how your cells function. Usually, your body gets rid of damaged cells before they turn cancerous, but this ability goes down as you age. Other factors that may affect your risk of developing cancer can include:
- Exposure to ultraviolet (UV) rays from the sun
- Smoking
- Your diet
- Physical inactivity
What are the symptoms of cancer?
Cancer symptoms depend on the type of cancer. For example, some of the symptoms that cancer may cause can include:
- A lump in your breast
- Blood in your urine (pee) or stool (poop)
- Bleeding or bruising for no known reason
- A sore that doesn't heal
- Trouble swallowing
- A new mole or a change to a mole you already have
Cancer may cause various symptoms but often doesn't cause pain. Don't wait until you're having pain before seeing your health care provider. See your provider if you have symptoms that don't get better in a few weeks.
How is cancer diagnosed?
There is no single test that can diagnose cancer. The tests ordered are usually based on your symptoms. Your provider may:
- Ask about your medical history
- Ask about your family health history, including relatives who have had cancer
- Do a physical exam
- Do a screening test such as a mammogram, colonoscopy, or a Pap test
- Order blood tests or imaging tests
To find out if you have cancer, your provider may order a biopsy. A biopsy is the procedure of removing and examining tissue, cells, or fluids from your body.
What are the treatments for cancer?
Treatment depends on the type of cancer and how advanced it is. Most treatment plans may include surgery, radiation, and/or chemotherapy. Some may involve hormone therapy, immunotherapy or other types of biological therapy, or stem cell transplantation.
Can cancer be prevented?
It's usually not possible to know exactly why cancer develops in some people but not others. There are some things that you can't control which may increase or decrease your risk of getting cancer, such as inheriting certain genes or your age. But some lifestyle habits may increase your risk of certain types of cancer. Avoid or reduce lifestyle habits such as:
- Smoking and tobacco use
- Having too much sun exposure
- Drinking too much alcohol
- Not getting enough physical activity
- Having obesity
NIH: National Cancer Institute
[Learn More in MedlinePlus]
Bone Cancer
Learn about bone cancer risk factors, signs and symptoms, tests to diagnose, factors affecting prognosis, staging, and treatment.[Learn More in MedlinePlus]
Primary Bone Cancer
Learn about the types of bone tumors and the methods used to diagnose and treat cancers that form from bone tissue.[Learn More in MedlinePlus]
Code History
- FY 2026 - No Change, effective from 10/1/2025 through 9/30/2026
- FY 2025 - No Change, effective from 10/1/2024 through 9/30/2025
- FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
- FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
- FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
- FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
- FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
- FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
- FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
- FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
- FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.
Footnotes
[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:
- The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
- The condition places limitations on self-care, independent living, and social interactions.
