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D12.1 ICD-10-CM Code: Benign neoplasm of appendix

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

Coding at a Glance

Tabular directives
1 Excludes1 · 2 Excludes2

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 393 — OTHER DIGESTIVE SYSTEM DIAGNOSES WITH MCC (MDC 06)
  • MS-DRG 394 — OTHER DIGESTIVE SYSTEM DIAGNOSES WITH CC (MDC 06)
  • MS-DRG 395 — OTHER DIGESTIVE SYSTEM DIAGNOSES WITHOUT CC/MCC (MDC 06)

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.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for D12.1 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 D12.1 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).

Excludes2 — Not Included Here

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

Source: inherited from D12

Coder workflow for D12.1

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

Before you code D12.1

  1. Confirm the documented site and behavior (this code’s block classifies benign 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 D12.1. 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 D12.1’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.

    ReviewD3A.020

Consider D12.1. 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 D12.1(1 note)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with D12.1: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareD3A.020

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

  • Excludes2 — not part of D12.1(2 notes)

    Coding workflow: The conditions named in this note are not included in D12.1. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareD3A.02, K63.5

    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 D12.1 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).

ReviewD3A.020

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

Benign neoplasm of appendix is a billable ICD-10-CM diagnosis code (D12.1).

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

Neoplasm Table Sites (2)

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

Anatomical sites from the official ICD-10-CM Table of Neoplasms that map to this code, with the matching behavior column.

  • Neoplasm, neoplastic, appendix — Benign
  • Neoplasm, neoplastic, intestine, intestinal, large, appendix — Benign

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 structured relationships — computed from published CMS and AHRQ datasets

Other codes that name D12.1 or its code family, from the CMS ICD-10-CM tabular instructional notes, the CMS Table of Neoplasms and the CMS Table of Neoplasms (site match derived from the code title). Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes2 note: K63.5 — Polyp of colon (via D12.-).

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

Referenced by 5 Same-site neoplasm codes: C18.1 — Malignant neoplasm of appendixCompare D12.1 vs C18.1 →, C78.5 — Secondary malignant neoplasm of large intestine and rectumCompare D12.1 vs C78.5 →, D01.0 — Carcinoma in situ of colonCompare D12.1 vs D01.0 →, D37.3 — Neoplasm of uncertain behavior of appendixCompare D12.1 vs D37.3 →, D49.0 — Neoplasm of unspecified behavior of digestive systemCompare D12.1 vs D49.0 →.

These codes represent related neoplasm behaviors affecting the same anatomic site.

Referenced by 7 Screening & history codes: Z12.13 — Encounter for screening for malignant neoplasm of small intestineCompare D12.1 vs Z12.13 →, Z85.03 — Personal history of malignant neoplasm of large intestineCompare D12.1 vs Z85.03 →, Z85.030 — Personal history of malignant carcinoid tumor of large intestineCompare D12.1 vs Z85.030 →, Z85.038 — Personal history of other malignant neoplasm of large intestineCompare D12.1 vs Z85.038 →, Z85.06 — Personal history of malignant neoplasm of small intestineCompare D12.1 vs Z85.06 →, Z85.060 — Personal history of malignant carcinoid tumor of small intestineCompare D12.1 vs Z85.060 →, Z85.068 — Personal history of other malignant neoplasm of small intestineCompare D12.1 vs Z85.068 →.

These codes represent screening tests and history codes that refer to this active disease condition.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 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 3 MS-DRGs: DRG 393 (MDC 06), DRG 394 (MDC 06), DRG 395 (MDC 06).

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

Clinical classification (AHRQ CCSR):NEO073 — Benign neoplasms (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 clinical category (CCSR)

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

D10.39 — Benign neoplasm of other parts of mouth, D10.4 — Benign neoplasm of tonsil, D10.5 — Benign neoplasm of other parts of oropharynx, D10.6 — Benign neoplasm of nasopharynx, D10.7 — Benign neoplasm of hypopharynx, D10.9 — Benign neoplasm of pharynx, unspecified, D11.0 — Benign neoplasm of parotid gland, D11.7 — Benign neoplasm of other major salivary glands, D11.9 — Benign neoplasm of major salivary gland, unspecified, D12.0 — Benign neoplasm of cecum, D12.2 — Benign neoplasm of ascending colon, D12.3 — Benign neoplasm of transverse colon, D12.4 — Benign neoplasm of descending colon, D12.5 — Benign neoplasm of sigmoid colon, D12.6 — Benign neoplasm of colon, unspecified, D12.7 — Benign neoplasm of rectosigmoid junction, D12.8 — Benign neoplasm of rectum, D12.9 — Benign neoplasm of anus and anal canal, D13.0 — Benign neoplasm of esophagus, D13.1 — Benign neoplasm of stomach, +252 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.

Fecal Occult Blood Test (FOBT), Iron Panel

Contextual Map

Every relationship of D12.1 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 D12.1 with these 2 related codes in Claim Check

Hierarchy

Excludes1

Same site

Referenced by Excludes2 notes

  • K63.5 — Polyp of colon[Excludes2](via D12.-): “adenomatous polyp of colon (D12.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Same-site neoplasm codes

Referenced by Screening & history codes MedCoder-derived

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

  • MDC 06 — Diseases and Disorders of the Digestive System[MDC crossing]: “Diseases and Disorders of the Digestive System — 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. 5,744 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Neoplasm sites

  • Neoplasm, neoplastic, appendix — Neoplasm, neoplastic, appendix — Benign [Neoplasm table]: “Neoplasm, neoplastic, appendix (Benign)”— CMS Table of Neoplasms · icd10cm-fy2026
  • Neoplasm, neoplastic, intestine, intestinal, large, appendix — Neoplasm, neoplastic, intestine, intestinal, large, appendix — Benign [Neoplasm table]: “Neoplasm, neoplastic, intestine, intestinal, large, appendix (Benign)”— CMS Table of Neoplasms · icd10cm-fy2026

Nearest codes (10)

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
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. "D12.1 — Benign neoplasm of appendix." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/d12.1-benign-neoplasm-of-appendix

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Benign neoplasm of appendix

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 D12.1 in its code family, with their registry titles.

View all codes in the D12 family