2027 ICD-10-CM Diagnosis Code C49.9Malignant neoplasm of connective and soft tissue, unspecified
ICD-10-CM Codes›C00–D49›C45-C49›C49
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Risk Adjusts — HCC 21
- Chronic Condition
C49.9 is a billable ICD-10-CM diagnosis code for malignant neoplasm of connective and soft tissue, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 542 through 544. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 2 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Sarcoma.
For Medicare Advantage risk adjustment, C49.9 maps to CMS-HCC Category 21 (Lymphoma and Other Cancers) under the V28 model, adding a risk factor of about 0.671 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
C49.9 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Adipocytic liposarcoma
- Alveolar rhabdomyosarcoma
- Alveolar soft part sarcoma
- Anaplastic embryonal rhabdomyosarcoma
- Angiosarcoma
- Biphasic synovial sarcoma
- Botryoid rhabdomyosarcoma
- Classic epithelioid sarcoma
- Cutaneous leiomyosarcoma
- Cutaneous leiomyosarcoma with granular cell change
- Dedifferentiated liposarcoma
- Desmoplastic small round cell tumor
- Ectomesenchymoma
- Embryonal rhabdomyosarcoma
- Epithelioid hemangioendothelioma
- Epithelioid leiomyosarcoma of skin
- Epithelioid liposarcoma
- Epithelioid myxofibrosarcoma
- Epithelioid sarcoma
- Ewing's sarcoma of soft tissue
- Extraskeletal myxoid chondrosarcoma
- Extraskeletal myxoid chondrosarcoma of soft tissue of limb
- Extraskeletal osteosarcoma
- Fibrosarcoma
- Fibrosarcoma of connective tissue
- Giant cell malignant fibrous histiocytoma of skin
- Hemangioendothelioma
- Infantile fibrosarcoma
- Inflammatory liposarcoma
- Inflammatory malignant fibrous histiocytoma of skin
- Intergroup rhabdomyosarcoma study post-surgical clinical group finding
- Intergroup rhabdomyosarcoma study post-surgical clinical group IIIA: Localized or locally extensive tumor, gross residual disease after biopsy only
- Intergroup rhabdomyosarcoma study post-surgical clinical group IIIB: Localized or locally extensive tumor, gross residual disease after major resection
- Intergroup rhabdomyosarcoma study post-surgical clinical group IV: Any size primary tumor, with or without regional lymph node involvement, with distant metastases, without respect to surgical approach to primary tumor
- Intimal sarcoma
- Intravascular angiosarcoma
- Leiomyomatous neoplasm of skin
- Leiomyosarcoma
- Leiomyosarcoma of connective tissue
- Lipoma-like liposarcoma
- Liposarcoma
- Liposarcoma of connective tissue
- Local recurrence of malignant neoplasm of soft tissue
- Low grade myofibroblastic sarcoma
- Low-grade fibromyxoid sarcoma
- Lymphangiosarcoma
- Malignant fibromatous neoplasm
- Malignant fibrous histiocytoma
- Malignant fibrous histiocytoma of skin
- Malignant granular cell tumor
- Malignant melanoma of soft tissues
- Malignant neoplasm of blood vessel
- Malignant neoplasm of bone, connective tissue, skin and breast
- Malignant neoplasm of connective tissue
- Malignant neoplasm of dermis
- Malignant neoplasm of fibrous tissue
- Malignant neoplasm of muscle
- Malignant neoplasm of soft tissue
- Malignant neoplasm of subcutaneous fibrous tissue
- Malignant ossifying fibromyxoid tumor
- Malignant phosphaturic mesenchymal neoplasm
- Malignant solitary fibrous tumor
- Malignant tenosynovial giant cell tumor
- Metastatic embryonal rhabdomyosarcoma
- Metastatic fibrosarcoma
- Metastatic infantile fibrosarcoma
- Metastatic myxofibrosarcoma
- Metastatic pleomorphic rhabdomyosarcoma
- Metastatic rhabdomyosarcoma
- Metastatic sarcoma to retroperitoneum
- Metastatic spindle cell rhabdomyosarcoma
- Metastatic synovial sarcoma
- Myxofibrosarcoma of skin
- Myxoid leiomyosarcoma of skin
- Myxoid liposarcoma
- Myxoid pleomorphic liposarcoma
- Myxoinflammatory fibroblastic sarcoma
- Pleomorphic liposarcoma
- Pleomorphic malignant fibrous histiocytoma of skin
- Pleomorphic rhabdomyosarcoma
- Poorly differentiated synovial sarcoma
- Primary alveolar soft part sarcoma
- Primary botryoid rhabdomyosarcoma
- Primary desmoplastic small round cell tumor
- Primary epithelioid hemangioendothelioma
- Primary epithelioid sarcoma
- Primary Ewing sarcoma of soft tissue
- Primary extraskeletal osteosarcoma
- Primary fibrosarcoma of connective tissue
- Primary leiomyosarcoma
- Primary liposarcoma of soft tissue of limb
- Primary malignant fibrous histiocytoma
- Primary malignant granular cell tumor
- Primary malignant neoplasm of blood vessel
- Primary malignant neoplasm of muscle
- Primary malignant neoplasm of soft tissues
- Primary myxofibrosarcoma
- Primary spindle cell rhabdomyosarcoma
- Primary synovial sarcoma
- Primary synovial sarcoma of soft tissue of limb
- Proximal epithelioid sarcoma
- Rhabdomyosarcoma
- Sarcoma
- Sarcoma of bone and connective tissue
- Sarcoma of connective tissue
- Sarcoma of soft tissue
- Sclerosing epithelioid fibrosarcoma
- Sclerosing liposarcoma
- Spindle cell liposarcoma
- Spindle cell rhabdomyosarcoma
- Spindle cell synovial sarcoma
- Superficial malignant fibrous histiocytoma of skin
- Surgical margin involved by sarcoma
- Surgical margin involvement by sarcoma cannot be assessed
- Surgical margin uninvolved by sarcoma
- Synovial sarcoma
- Undifferentiated pleomorphic sarcoma
- Undifferentiated round cell sarcoma
- Undifferentiated sarcoma
- Undifferentiated spindle cell sarcoma
- Vaccine-induced fibrosarcoma
- Well differentiated liposarcoma
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to C49.9: its own notes plus those printed at C49 and Chapter 2. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- malignant neoplasm of blood vessel
- malignant neoplasm of bursa
- malignant neoplasm of cartilage
- malignant neoplasm of fascia
- malignant neoplasm of fat
- malignant neoplasm of ligament, except uterine
- malignant neoplasm of lymphatic vessel
- malignant neoplasm of muscle
- malignant neoplasm of synovia
- malignant neoplasm of tendon (sheath)
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- Kaposi's sarcoma of soft tissue (C46.1)
- malignant neoplasm of heart (C38.0)
- malignant neoplasm of peripheral nerves and autonomic nervous system (C47.-)
- malignant neoplasm of peritoneum (C48.2)
- malignant neoplasm of retroperitoneum (C48.0)
- malignant neoplasm of uterine ligament (C57.3)
- mesothelioma (C45.-)
Notes
General instructions on how these codes are used.
- Functional activity
- All neoplasms are classified in this chapter, whether they are functionally active or not. An additional code from Chapter 4 may be used, to identify functional activity associated with any neoplasm.
- Morphology [Histology]
- Chapter 2 classifies neoplasms primarily by site (topography), with broad groupings for behavior, malignant, in situ, benign, etc. The Table of Neoplasms should be used to identify the correct topography code. In a few cases, such as for malignant melanoma and certain neuroendocrine tumors, the morphology (histologic type) is included in the category and codes.
- Primary malignant neoplasms overlapping site boundaries
- A primary malignant neoplasm that overlaps two or more contiguous (next to each other) sites should be classified to the subcategory/code .8 ('overlapping lesion'), unless the combination is specifically indexed elsewhere. For multiple neoplasms of the same site that are not contiguous, such as tumors in different quadrants of the same breast, codes for each site should be assigned.
- Malignant neoplasm of ectopic tissue
- Malignant neoplasms of ectopic tissue are to be coded to the site mentioned, e.g., ectopic pancreatic malignant neoplasms are coded to pancreas, unspecified (C25.9).
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name C49.9, its category, or a range that includes it.
Applicable To 1
These notes mention C49.9.
- Z85.83 Personal history of malignant neoplasm of bone and soft tissue
Excludes1 1
These codes carry an Excludes1 note naming C49.9: they are not reported together with it, unless the two conditions are unrelated.
- Block C40-C41 Malignant neoplasms of bone and articular cartilagemalignant neoplasm of synovia (C49.-) names C49.-, which includes this code
Code First 1
These codes say to code first a condition named in the note, and C49.9 is one of the conditions named.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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. |
|---|---|---|---|---|---|---|
| aponeurosis | C49.9 | C79.89 | – | D21.9 | D48.1 | D49.2 |
| connective tissue NEC | C49.9 | C79.89 | – | D21.9 | D48.1 | D49.2 |
| connective tissue NEC › extremity | C49.9 | C79.89 | – | D21.9 | D48.1 | D49.2 |
| connective tissue NEC › limb NEC | C49.9 | C79.89 | – | D21.9 | D48.1 | D49.2 |
| lymph, lymphatic channel NEC | C49.9 | C79.89 | – | D21.9 | D48.1 | D49.2 |
| lymph, lymphatic channel NEC › vessel [See Also: Neoplasm, connective tissue] | C49.9 | C79.89 | – | D21.9 | D48.1 | D49.2 |
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Convert C49.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About C49.9Overview
What is the ICD-10 code for malignant neoplasm of connective and soft tissue, unspecified?
The ICD-10-CM code for malignant neoplasm of connective and soft tissue, unspecified is C49.9 (sometimes written as C499). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is C49.9 (Malignant neoplasm of other connective and soft tissue) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of connective and soft tissue, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does C49.9 group to?
When malignant neoplasm of connective and soft tissue, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 543, 544, 542, with relative weights from 0.7404 to 1.7208 depending on complications. Higher weights mean higher Medicare reimbursement.
Is C49.9 a CC or MCC?
CMS lists C49.9 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 2 closely related codes in its exclusion list.
Can C49.9 be reported with C32.3?
Not as a rule. The Excludes1 note at C49, which applies to C49.9, lists "larynx (C32.3)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What HCC is C49.9?
C49.9 (malignant neoplasm of connective and soft tissue, unspecified) maps to CMS-HCC Category 21 (Lymphoma and Other Cancers), commonly written as HCC 21, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 10 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 22.
Does C49.9 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, C49.9 adds a risk adjustment factor of about 0.671 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.493 to 0.739 depending on the payment segment). A more severe related category (HCC 17, HCC 18, HCC 19, and HCC 20) supersedes it when both are reported. See the full factor table on the HCC 21 category page.
