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C46.9 ICD-10-CM Code: Kaposi's sarcoma, unspecified

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
1 inclusion term · 1 code-first instruction
Risk adjustment
CMS-HCC V28: 1 category · CMS-HCC V22 category 10 · RxHCC V08 category 20

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.

  • MS-DRG 606 — MINOR SKIN DISORDERS WITH MCC (MDC 09)
  • MS-DRG 607 — MINOR SKIN DISORDERS WITHOUT MCC (MDC 09)
  • MS-DRG 974 — HIV WITH MAJOR RELATED CONDITION WITH MCC (MDC 25)
  • MS-DRG 975 — HIV WITH MAJOR RELATED CONDITION WITH CC (MDC 25)
  • MS-DRG 976 — HIV WITH MAJOR RELATED CONDITION WITHOUT CC/MCC (MDC 25)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Risk Adjustment (CMS-HCC)

Payment categories this diagnosis maps to under CMS-HCC V28, payment year 2026.

  • HCC 21 — Lymphoma and Other Cancers (supersedes HCC 22, HCC 23)

Other models: CMS-HCC V22 HCC 10 · RxHCC V08 HCC 20

Risk scores depend on the enrollee's full accepted diagnosis set and segment; a category mapping alone does not determine payment.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for C46.9 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on C46.9 itself; “inherited from” names the category or block whose note applies here.

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Kaposi's sarcoma of unspecified site

Code First

Underlying conditions that must be sequenced before this code.

  • any human immunodeficiency virus [HIV] disease (B20)

Source: inherited from C46

Coder workflow for C46.9

MedCoder structured workflow — derived from this code’s own official record

Before you code C46.9

  1. Unspecified does not mean incorrect. When the record gives no greater specificity, C46.9 may be the appropriate code. Check the record for detail that supports a more specific sibling. An unspecified code is for records that do not provide the detail a more specific code needs; a query, not an assumption, is the route to specificity (Guidelines I.A.9.b, I.B.18).

    ReviewC46.0, C46.1, C46.2, C46.3, C46.4, C46.5, C46.7

    See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →

  2. Confirm the documented site and behavior (this code’s block classifies malignant neoplasms), whether the site is primary or secondary, and whether the malignancy is current or a personal history: a previously excised malignancy with no further treatment and no evidence of disease is history, not current disease. Verify the site against the Table of Neoplasms. Neoplasm chapter guidelines (Guidelines I.C.2.a, I.C.2.d, I.C.2.m).

    See the Table of Neoplasms entries · Guide: Active cancer vs history of cancer →

Choose the right path

  1. Does the record document the detail a more specific sibling code needs?
    Yes → Review the specific siblings in this subcategory.
    No → Continue — C46.9 is appropriate when the documentation goes no further.

    ReviewC46.0, C46.1, C46.2, C46.3, C46.4, C46.5, C46.7

  2. Is the underlying (etiologic) condition the Code First note names documented?
    Yes → Sequence the underlying condition first, then C46.9.
    No → Continue; do not add an underlying condition the record does not document.

    ReviewB20

Consider C46.9. Then confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
Anatomical site
At the most specific level the record states; a site the classification separates cannot be assumed from a procedure or a measurement.
The underlying (etiologic) condition
Named in the Code First note; sequenced before this code when documented (Guidelines I.A.13).
Behavior and current-versus-history status
Malignant, in situ, benign or uncertain; primary or secondary; current disease or personal history (Guidelines I.C.2.m).
Any detail beyond this code’s title
What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.

Official instructions as workflow

  • Code First — sequencing check(1 note)

    Coding workflow: Check whether the underlying or etiologic condition the note names is documented. When it is, sequence it before C46.9. Do not add an underlying condition the record does not document.

    ReviewB20

    See the official tabular notes · Guidelines I.A.13

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: The provider documents the condition in the terms of this code’s title and records no further detail.

Coding question: Is a more specific sibling code supportable?

Path: Review the specific siblings in this subcategory and what each requires the record to state.

Reason: A more specific code needs documentation of the distinguishing element; without it the unspecified code is appropriate, and a provider query is the route to specificity (Guidelines I.A.9.b, I.B.18).

ReviewC46.0, C46.1, C46.2, C46.3, C46.4, C46.5, C46.7

Documentation: The underlying condition the Code First note names is documented alongside this condition.

Coding question: How are the two sequenced?

Path: Review the Code First note.

Reason: The underlying condition is sequenced first and the manifestation follows (Guidelines I.A.13).

ReviewB20

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Code Overview

Kaposi's sarcoma, unspecified is a billable ICD-10-CM diagnosis code (C46.9).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Indexed Clinical Terms (2)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Verify Before Coding

  • CC as a secondary diagnosis (FY2026). Can raise the stay's MS-DRG severity tier.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name C46.9 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes2 note: D47.Z2 — Castleman disease (via C46.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: CC — Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 409 clinically related codes on its CMS exclusion list. Does not count toward severity when the stay groups to DRGs 974-976 (HIV with Major Related Condition).

Named in the grouper logic of 5 MS-DRGs: DRG 606 (MDC 09), DRG 607 (MDC 09), DRG 974 (MDC 25), DRG 975 (MDC 25), DRG 976 (MDC 25).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):NEO024 — Sarcoma (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same CMS-HCC risk category (V28)

CMS maps these diagnoses to the same Hierarchical Condition Category (Lymphoma and Other Cancers) for risk-adjusted payment.

C41.9 — Malignant neoplasm of bone and articular cartilage, unspecified, C46.0 — Kaposi's sarcoma of skin, C46.1 — Kaposi's sarcoma of soft tissue, C46.2 — Kaposi's sarcoma of palate, C46.3 — Kaposi's sarcoma of lymph nodes, C46.4 — Kaposi's sarcoma of gastrointestinal sites, C46.50 — Kaposi's sarcoma of unspecified lung, C46.51 — Kaposi's sarcoma of right lung, C46.52 — Kaposi's sarcoma of left lung, C46.7 — Kaposi's sarcoma of other sites, C47.0 — Malignant neoplasm of peripheral nerves of head, face and neck, C47.10 — Malignant neoplasm of peripheral nerves of unspecified upper limb, including shoulder, C47.11 — Malignant neoplasm of peripheral nerves of right upper limb, including shoulder, C47.12 — Malignant neoplasm of peripheral nerves of left upper limb, including shoulder, C47.20 — Malignant neoplasm of peripheral nerves of unspecified lower limb, including hip, C47.21 — Malignant neoplasm of peripheral nerves of right lower limb, including hip, C47.22 — Malignant neoplasm of peripheral nerves of left lower limb, including hip, C47.3 — Malignant neoplasm of peripheral nerves of thorax, C47.5 — Malignant neoplasm of peripheral nerves of pelvis, C47.6 — Malignant neoplasm of peripheral nerves of trunk, unspecified, +442 more

Related risk categories

These categories interact through CMS's HCC hierarchy — one can suppress the other's risk-adjustment weight when both are present on a claim.

Cancer Metastatic to Lung, Liver, Brain, and Other Organs; Acute Myeloid Leukemia Except Promyelocytic, Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer; Acute Leukemia Except Myeloid, Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers, Lung and Other Severe Cancers, Bladder, Colorectal, and Other Cancers, Prostate, Breast, and Other Cancers and Tumors

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Sarcoma).

C46.0 — Kaposi's sarcoma of skin, C46.1 — Kaposi's sarcoma of soft tissue, C46.2 — Kaposi's sarcoma of palate, C46.3 — Kaposi's sarcoma of lymph nodes, C46.4 — Kaposi's sarcoma of gastrointestinal sites, C46.50 — Kaposi's sarcoma of unspecified lung, C46.51 — Kaposi's sarcoma of right lung, C46.52 — Kaposi's sarcoma of left lung, C46.7 — Kaposi's sarcoma of other sites, C49.0 — Malignant neoplasm of connective and soft tissue of head, face and neck, C49.10 — Malignant neoplasm of connective and soft tissue of unspecified upper limb, including shoulder, C49.11 — Malignant neoplasm of connective and soft tissue of right upper limb, including shoulder, C49.12 — Malignant neoplasm of connective and soft tissue of left upper limb, including shoulder, C49.20 — Malignant neoplasm of connective and soft tissue of unspecified lower limb, including hip, C49.21 — Malignant neoplasm of connective and soft tissue of right lower limb, including hip, C49.22 — Malignant neoplasm of connective and soft tissue of left lower limb, including hip, C49.3 — Malignant neoplasm of connective and soft tissue of thorax, C49.4 — Malignant neoplasm of connective and soft tissue of abdomen, C49.5 — Malignant neoplasm of connective and soft tissue of pelvis, C49.6 — Malignant neoplasm of connective and soft tissue of trunk, unspecified, +5 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main terms “Sarcoma”, “Kaposi's”; these codes share that main term but sit in a different category of the Tabular List.

B00.0 — Eczema herpeticum (varicelliform eruption), C22.3 — Angiosarcoma of liver (Kupffer cell), C22.4 — Other sarcomas of liver (liver NEC), C41.0 — Malignant neoplasm of bones of skull and face (odontogenic, upper jaw), C41.1 — Malignant neoplasm of mandible (odontogenic), C54.0 — Malignant neoplasm of isthmus uteri (stromal, isthmus), C54.1 — Malignant neoplasm of endometrium (stromal), C71.6 — Malignant neoplasm of cerebellum (cerebellar), C71.9 — Malignant neoplasm of brain, unspecified (monstrocellular, unspecified site), C92.3 — Myeloid sarcoma (myeloid), C96.22 — Mast cell sarcoma (mast cell), C96.4 — Sarcoma of dendritic cells (accessory cells) (Langerhans cell), C96.A — Histiocytic sarcoma (histiocytic), L44.0 — Pityriasis rubra pilaris (lichen ruber), Q82.1 — Xeroderma pigmentosum (dermatosis), T88.1 — Other complications following immunization, not elsewhere classified (varicelliform eruption, vaccinia)

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

Gamma-glutamyl Transferase (GGT) Test, HIV Screening Test, Iron Panel

Contextual Map

Every relationship of C46.9 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run C46.9 with this related code in Claim Check

Hierarchy

Referenced by Excludes2 notes

  • D47.Z2 — Castleman disease[Excludes2](via C46.-): “Kaposi's sarcoma (C46.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

Risk adjustment (CMS-HCC)

  • HCC 21 — Lymphoma and Other Cancers [CMS-HCC]: “Lymphoma and Other Cancers — supersedes HCC 22 (Bladder, Colorectal, and Other Cancers), HCC 23 (Prostate, Breast, and Other Cancers and Tumors)”— CMS-HCC V28 · 2026

MS-DRG Grouper

MDC crossing

  • MDC 09 — Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast[MDC crossing]: “Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 7,376 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026
  • MDC 25 — Human Immunodeficiency Virus Infections[MDC crossing]: “Human Immunodeficiency Virus Infections — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

  • Kaposi's, sarcoma, unspecified site[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Sarcoma (of), Kaposi's, unspecified site[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (11)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page
Risk adjustment Official source data
2026 Mid-Year Final ICD-10 Mappings + Model Software (cms.gov/files/zip/2026-midyear-final-icd-10-mappings.zip, 2026-midyear-final-model-software.zip) — CMS-HCC V28, PY2026 mid-year final release Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "C46.9 — Kaposi's sarcoma, unspecified." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/c46.9-kaposis-sarcoma-unspecified

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Kaposi's sarcoma, unspecified

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to C46.9 in its code family, with their registry titles.

View all codes in the C46 family