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C43.31 ICD-10-CM Code: Malignant melanoma of nose

Compare with another codeCheck this code on a claim

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

Coding at a Glance

Tabular directives
1 Excludes1 · 3 Excludes2
Risk adjustment
CMS-HCC V28: 1 category · CMS-HCC V22 category 12 · RxHCC V08 category 22

Billable · FY2027A valid, specific ICD-10-CM code, reportable for dates of service in FY2027.

What you need to know

Source: CMS/NCHS Official ICD-10-CM tabular notes, quoted. From the CMS/NCHS tabular list for the release in force. A note the category or block publishes applies to this code too; the Instructions section marks which is which.

Excludes1Never report with this code
  • melanoma in situ (D03.-)
Excludes2Not included here; may be reported together
  • malignant melanoma of skin of genital organs (C51-C52, C60.-, C63.-)
  • Merkel cell carcinoma (C4A.-)
  • sites other than skin-code to malignant neoplasm of the site

Most relevant related codes MedCoder-derived

Read off the official notes above and this code’s own position in the tabular list. Which to report is a documentation question; Compare shows the two side by side.

CompareCheck ClaimView Related Codes

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 v44, Appendix B.

  • MS-DRG 595 — MAJOR SKIN DISORDERS WITH MCC (MDC 09)
  • MS-DRG 596 — MAJOR SKIN DISORDERS WITHOUT MCC (MDC 09)

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 23 — Prostate, Breast, and Other Cancers and Tumors

Other models: CMS-HCC V22 HCC 12 · RxHCC V08 HCC 22

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 C43.31 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2027Effective: October 1, 2026

Trace:FY2027 changesChange historyRelease, file and checksum

Notes without a marker are published on C43.31 itself; “inherited from” names the category or block whose note applies here.

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Source: inherited from C43

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

Source: inherited from C43

Coder workflow for C43.31

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

Before you code C43.31

  1. 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 →

  2. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with C43.31. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Does the documentation support a condition named in C43.31’s Excludes1 note?
    Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
    No → Continue.

    ReviewD03

Consider C43.31. 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.
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).

Official instructions as workflow

  • Excludes1 — check before selecting C43.31(1 note)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with C43.31: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareD03

    See the official tabular notes · Guidelines I.A.12.a

  • Excludes2 — not part of C43.31(3 notes)

    Coding workflow: The conditions named in this note are not included in C43.31. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareC60, C63, C4A

    See the official tabular notes · Guidelines I.A.12.b

Coding decision scenarios

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

Documentation: Both the condition C43.31 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewD03

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.

Don’t confuse C43.31 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of C43.31 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

  • D03— Excludes1 conflict (Excludes1 — generally not reported together)

    Not coded here — the tabular list excludes this pair for the same encounter.

    Not reported together with this code, except where the two conditions are documented as unrelated.

    What moves you there: Documentation of melanoma in situ moves the case to D03; the two are not reported together unless documented as unrelated.

    Full comparison: C43.31 vs D03 →

  • C43.30— Specificity relationship (Review)

    Overlapping diagnoses in the same category.

    Overlapping codes in the same category — the documentation decides which is the more specific fit.

    What moves you there: A record that documents no more than “Malignant melanoma of unspecified part of face” takes C43.30; specificity in the record moves it back here.

    Full comparison: C43.31 vs C43.30 →

  • C51— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of malignant melanoma of skin of genital organs adds C51; it is not part of this code and both may be reported when both are documented.

    Full comparison: C43.31 vs C51 →

  • C52— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of malignant melanoma of skin of genital organs adds C52; it is not part of this code and both may be reported when both are documented.

    Full comparison: C43.31 vs C52 →

  • C60— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of malignant melanoma of skin of genital organs adds C60; it is not part of this code and both may be reported when both are documented.

    Full comparison: C43.31 vs C60 →

  • C63— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of malignant melanoma of skin of genital organs adds C63; it is not part of this code and both may be reported when both are documented.

    Full comparison: C43.31 vs C63 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Coding context

Guidelines, coding notes, decision aids, relationships (with MS-DRG and CCSR classification), hierarchy, HCC, coverage and the context map: what a coder reaches for after the core. Each section names whether it is official source data, a MedCoder-derived relationship or MedCoder editorial.

Code Overview

Malignant melanoma of nose is a billable ICD-10-CM diagnosis code (C43.31).

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

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

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-derived relationships — computed from published CMS and AHRQ datasets

Other codes that name C43.31 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 2 Excludes1 notes: C30.0 — Malignant neoplasm of nasal cavity, C44 — Other and unspecified malignant neoplasm of skin (via C43.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.

Named in the grouper logic of 2 MS-DRGs: DRG 595 (MDC 09), DRG 596 (MDC 09).

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

Clinical classification (AHRQ CCSR):NEO025 — Skin cancers - melanoma (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 (Prostate, Breast, and Other Cancers and Tumors) for risk-adjusted payment.

C43.0 — Malignant melanoma of lip, C43.10 — Malignant melanoma of unspecified eyelid, including canthus, C43.111 — Malignant melanoma of right upper eyelid, including canthus, C43.112 — Malignant melanoma of right lower eyelid, including canthus, C43.121 — Malignant melanoma of left upper eyelid, including canthus, C43.122 — Malignant melanoma of left lower eyelid, including canthus, C43.20 — Malignant melanoma of unspecified ear and external auricular canal, C43.21 — Malignant melanoma of right ear and external auricular canal, C43.22 — Malignant melanoma of left ear and external auricular canal, C43.30 — Malignant melanoma of unspecified part of face, C43.39 — Malignant melanoma of other parts of face, C43.4 — Malignant melanoma of scalp and neck, C43.51 — Malignant melanoma of anal skin, C43.52 — Malignant melanoma of skin of breast, C43.59 — Malignant melanoma of other part of trunk, C43.60 — Malignant melanoma of unspecified upper limb, including shoulder, C43.61 — Malignant melanoma of right upper limb, including shoulder, C43.62 — Malignant melanoma of left upper limb, including shoulder, C43.70 — Malignant melanoma of unspecified lower limb, including hip, C43.71 — Malignant melanoma of right lower limb, including hip, +213 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, Lymphoma and Other Cancers, Bladder, Colorectal, and Other Cancers

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Skin cancers - melanoma).

C43.11 — Malignant melanoma of right eyelid, including canthus, C43.111 — Malignant melanoma of right upper eyelid, including canthus, C43.112 — Malignant melanoma of right lower eyelid, including canthus, C43.12 — Malignant melanoma of left eyelid, including canthus, C43.121 — Malignant melanoma of left upper eyelid, including canthus, C43.122 — Malignant melanoma of left lower eyelid, including canthus, C43.20 — Malignant melanoma of unspecified ear and external auricular canal, C43.21 — Malignant melanoma of right ear and external auricular canal, C43.22 — Malignant melanoma of left ear and external auricular canal, C43.30 — Malignant melanoma of unspecified part of face, C43.39 — Malignant melanoma of other parts of face, C43.4 — Malignant melanoma of scalp and neck, C43.51 — Malignant melanoma of anal skin, C43.52 — Malignant melanoma of skin of breast, C43.59 — Malignant melanoma of other part of trunk, C43.60 — Malignant melanoma of unspecified upper limb, including shoulder, C43.61 — Malignant melanoma of right upper limb, including shoulder, C43.62 — Malignant melanoma of left upper limb, including shoulder, C43.70 — Malignant melanoma of unspecified lower limb, including hip, C43.71 — Malignant melanoma of right lower limb, including hip, +30 more

Same Index main term, other category

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

C51.0 — Malignant neoplasm of labium majus (skin, labium, majus), C51.1 — Malignant neoplasm of labium minus (skin, labium, minus), C51.8 — Malignant neoplasm of overlapping sites of vulva (skin, vulva, overlapping sites), C51.9 — Malignant neoplasm of vulva, unspecified (skin, vulva), C60.0 — Malignant neoplasm of prepuce (skin, prepuce), C60.9 — Malignant neoplasm of penis, unspecified (skin, penis), C63.2 — Malignant neoplasm of scrotum (skin, scrotum), C63.9 — Malignant neoplasm of male genital organ, unspecified (skin, male genital organ NEC), C69.4 — Malignant neoplasm of ciliary body (spindle cell, type B), C79.81 — Secondary malignant neoplasm of breast (metastatic, breast), C79.82 — Secondary malignant neoplasm of genital organs (metastatic, genital organ), C79.89 — Secondary malignant neoplasm of other specified sites (metastatic, specified site NEC), D03.0 — Melanoma in situ of lip (in situ, lip), D03.1 — Melanoma in situ of eyelid, including canthus (in situ, eyelid), D03.2 — Melanoma in situ of ear and external auricular canal (in situ, ear), D03.30 — Melanoma in situ of unspecified part of face (in situ, face), D03.39 — Melanoma in situ of other parts of face (in situ, jaw), D03.4 — Melanoma in situ of scalp and neck (in situ, neck), D03.51 — Melanoma in situ of anal skin (in situ, perineum), D03.52 — Melanoma in situ of breast (skin) (soft tissue) (in situ, breast), +5 more

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, Iron Panel

Contextual Map

Every relationship of C43.31 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 C43.31 with these 2 related codes in Claim Check

Hierarchy

Referenced by Excludes1 notes

Clinical classification (CCSR)

Risk adjustment (CMS-HCC)

  • HCC 23 — Prostate, Breast, and Other Cancers and Tumors [CMS-HCC]— 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. 7,378 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027

Index entries

  • Melanoma (malignant), skin, ala nasi[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Melanoma (malignant), skin, nose (external)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027

Nearest codes (32)

Change history

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

Reference

Index terms and tables, published questions and FAQ, every source behind this page with its release and checksum, the date-of-service check and the complete change history.

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.

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 FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v44.0 (October 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 — v44 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-derived 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 editorial 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.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 20, 2026 · All releases and sources

Labels on this page: Official source data · MedCoder-derived relationship · MedCoder editorial explanation. How to read the labels · All data sources and release dates · CMS coding rules

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. "C43.31 — Malignant melanoma of nose." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/c43.31-malignant-melanoma-of-nose

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Malignant melanoma of nose

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027, 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 C43.31 in its code family, with their registry titles.

View all codes in the C43 family