2027 ICD-10-CM Diagnosis Code C46.1Kaposi's sarcoma of soft tissue
ICD-10-CM Codes›C00–D49›C45-C49›C46
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Risk Adjusts — HCC 21
- Chronic Condition
C46.1 is a billable ICD-10-CM diagnosis code for Kaposi's sarcoma of soft tissue. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 606 through 607, 974 through 976. 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 4 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Sarcoma.
For Medicare Advantage risk adjustment, C46.1 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
C46.1 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.
- Kaposi's sarcoma of soft tissue
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to C46.1: its own notes plus those printed at C46 and Chapter 2. A note printed at a category, block or chapter applies to every code under it.
Applicable To
Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.
- Kaposi's sarcoma of blood vessel
- Kaposi's sarcoma of connective tissue
- Kaposi's sarcoma of fascia
- Kaposi's sarcoma of ligament
- Kaposi's sarcoma of lymphatic(s) NEC
- Kaposi's sarcoma of muscle
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 lymph glands and nodes (C46.3)
Code First
The underlying condition named in the note is sequenced before this code.
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 C46.1, its category, or a range that includes it.
Applicable To 1
These notes mention C46.1.
- Z85.83 Personal history of malignant neoplasm of bone and soft tissue
Excludes1 2
These codes carry an Excludes1 note naming C46.1: they are not reported together with it, unless the two conditions are unrelated.
Excludes2 2
These codes carry an Excludes2 note naming C46.1: its condition is not part of those codes, and both may be reported when the patient has both.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
connective tissue C46.1
Sarcoma (of) See Also: Neoplasm, connective tissue, malignant;
connective tissue C46.1
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Sarcoma, Kaposi
a multicentric, malignant neoplastic vascular proliferation characterized by the development of bluish-red cutaneous nodules, usually on the lower extremities, most often on the toes or feet, and slowly increasing in size and number and spreading to more proximal areas. the tumors have endothelium-lined channels and vascular spaces admixed with variably sized aggregates of spindle-shaped cells, and often remain confined to the skin and subcutaneous tissue, but widespread visceral involvement may occur. kaposi's sarcoma occurs spontaneously in jewish and italian males in europe and the united states. an aggressive variant in young children is endemic in some areas of africa. a third form occurs in about 0.04% of kidney transplant patients. there is also a high incidence in aids patients. (from dorland, 27th ed & holland et al., cancer medicine, 3d ed, pp2105-7) hhv-8 is the suspected cause.
Patient EducationClinical
Kaposi Sarcoma
Kaposi sarcoma, sometimes called KS, is a type of cancer. It causes lesions (abnormal tissue) to grow in different parts of the body, including:
The full article covers:
- What is Kaposi sarcoma?
- What causes Kaposi sarcoma and who is more likely to develop it?
- What are the symptoms of Kaposi sarcoma?
- How is Kaposi sarcoma diagnosed?
- What are the treatments for Kaposi sarcoma?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert C46.1 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About C46.1Overview
What is the ICD-10 code for Kaposi's sarcoma of soft tissue?
The ICD-10-CM code for Kaposi's sarcoma of soft tissue is C46.1 (sometimes written as C461). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is C46.1 (Kaposi's sarcoma) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report Kaposi's sarcoma of soft tissue on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does C46.1 group to?
When Kaposi's sarcoma of soft tissue is the principal diagnosis on an inpatient stay, it groups to MS-DRG 974, 976, 607, 975, 606, with relative weights from 0.7879 to 3.0488 depending on complications. Higher weights mean higher Medicare reimbursement.
Is C46.1 a CC or MCC?
CMS lists C46.1 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 4 closely related codes in its exclusion list.
What is coded first with C46.1?
The Code First note at C46, which applies to C46.1, reads: any human immunodeficiency virus [HIV] disease (B20). When one of these applies, it is sequenced before C46.1.
What HCC is C46.1?
C46.1 (Kaposi's sarcoma of soft tissue) 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 20.
Does C46.1 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, C46.1 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.
