Skip to main content

D37.3 ICD-10-CM Code: Neoplasm of uncertain behavior of appendix

Compare with another code for D37.3Check 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
2 Excludes1

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, and is marked with where it comes from.

Excludes1Not reported with this code unless documented as unrelated
  • stromal tumors of uncertain behavior of digestive system (D48.1-) (from D37)
  • neoplasms of unspecified behavior (D49.-) (from D37-D48)

Where it sits Source: CMS/NCHS

Under:Chapter 2: NeoplasmsD37-D48 Neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromesD37 Neoplasm of uncertain behavior of oral cavity and digestive organs

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 374 — DIGESTIVE MALIGNANCY WITH MCC (MDC 06)
  • MS-DRG 375 — DIGESTIVE MALIGNANCY WITH CC (MDC 06)
  • MS-DRG 376 — DIGESTIVE MALIGNANCY 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 D37.3 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 D37.3 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).

Coder workflow for D37.3

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

Before you code D37.3

  1. Confirm the documented site and behavior (this code’s block classifies uncertain behavior 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 D37.3. 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 D37.3’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.

    ReviewD48.1, D49

Consider D37.3. 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 D37.3(2 notes)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with D37.3: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareD48.1, D49

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

Coding decision scenarios

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

Documentation: Both the condition D37.3 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).

ReviewD48.1, D49

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 D37.3 with…

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

The codes most likely to be picked instead of D37.3 — 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.

  • D48.1— 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 stromal tumors of uncertain behavior of digestive system moves the case to D48.1; the two are not reported together unless documented as unrelated.

    Full comparison: D37.3 vs D48.1 →

  • D49— 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 neoplasms of unspecified behavior moves the case to D49; the two are not reported together unless documented as unrelated.

    Full comparison: D37.3 vs D49 →

  • D37.9— 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 “Neoplasm of uncertain behavior of digestive organ, unspecified” takes D37.9; specificity in the record moves it back here.

    Full comparison: D37.3 vs D37.9 →

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

Neoplasm of uncertain behavior of appendix is a billable ICD-10-CM diagnosis code (D37.3).

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 D37.3 or its code family, from the CMS ICD-10-CM tabular instructional notes and the CMS Table of Neoplasms. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes2 note: D49 — Neoplasms of unspecified behavior (via D37.-).

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 D37.3 vs C18.1 →, C78.5 — Secondary malignant neoplasm of large intestine and rectumCompare D37.3 vs C78.5 →, D01.0 — Carcinoma in situ of colonCompare D37.3 vs D01.0 →, D12.1 — Benign neoplasm of appendixCompare D37.3 vs D12.1 →, D49.0 — Neoplasm of unspecified behavior of digestive systemCompare D37.3 vs D49.0 →.

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

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 3 MS-DRGs: DRG 374 (MDC 06), DRG 375 (MDC 06), DRG 376 (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):NEO072 — Neoplasms of unspecified nature or uncertain behavior (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 (Neoplasms of unspecified nature or uncertain behavior).

D37.02 — Neoplasm of uncertain behavior of tongue, D37.030 — Neoplasm of uncertain behavior of the parotid salivary glands, D37.031 — Neoplasm of uncertain behavior of the sublingual salivary glands, D37.032 — Neoplasm of uncertain behavior of the submandibular salivary glands, D37.039 — Neoplasm of uncertain behavior of the major salivary glands, unspecified, D37.04 — Neoplasm of uncertain behavior of the minor salivary glands, D37.05 — Neoplasm of uncertain behavior of pharynx, D37.09 — Neoplasm of uncertain behavior of other specified sites of the oral cavity, D37.1 — Neoplasm of uncertain behavior of stomach, D37.2 — Neoplasm of uncertain behavior of small intestine, D37.4 — Neoplasm of uncertain behavior of colon, D37.5 — Neoplasm of uncertain behavior of rectum, D37.6 — Neoplasm of uncertain behavior of liver, gallbladder and bile ducts, D37.8 — Neoplasm of uncertain behavior of other specified digestive organs, D37.9 — Neoplasm of uncertain behavior of digestive organ, unspecified, D38.0 — Neoplasm of uncertain behavior of larynx, D38.1 — Neoplasm of uncertain behavior of trachea, bronchus and lung, D38.2 — Neoplasm of uncertain behavior of pleura, D38.3 — Neoplasm of uncertain behavior of mediastinum, D38.4 — Neoplasm of uncertain behavior of thymus, +100 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.

CEA Test, Fecal Occult Blood Test (FOBT), Gamma-glutamyl Transferase (GGT) Test, Iron Panel

Contextual Map

Every relationship of D37.3 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 D37.3 with this related code in Claim Check

Hierarchy

Same site

Referenced by Excludes2 notes

Referenced by Same-site neoplasm codes

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. 5,748 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027

Neoplasm sites

  • Neoplasm, neoplastic, appendix — Neoplasm, neoplastic, appendix — Uncertain Behavior [Neoplasm table]: “Neoplasm, neoplastic, appendix (Uncertain Behavior)”— CMS Table of Neoplasms · icd10cm-fy2027
  • Neoplasm, neoplastic, intestine, intestinal, large, appendix — Neoplasm, neoplastic, intestine, intestinal, large, appendix — Uncertain Behavior [Neoplasm table]: “Neoplasm, neoplastic, intestine, intestinal, large, appendix (Uncertain Behavior)”— CMS Table of Neoplasms · icd10cm-fy2027

Nearest codes (19)

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.

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 — Uncertain Behavior
  • Neoplasm, neoplastic, intestine, intestinal, large, appendix — Uncertain Behavior

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
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 28, 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. "D37.3 — Neoplasm of uncertain behavior of appendix." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/d37.3-neoplasm-of-uncertain-behavior-of-appendix

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Neoplasm of uncertain behavior of appendix

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 D37.3 in its code family, with their registry titles.

View all codes in the D37 family