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D09.9 ICD-10-CM Code: Carcinoma in situ, unspecified

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

Coding at a Glance

Tabular directives
4 inclusion terms · 1 Excludes1

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 826 — MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASMS WITH MAJOR O.R. PROCEDURES WITH MCC (MDC 17)
  • MS-DRG 827 — MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASMS WITH MAJOR O.R. PROCEDURES WITH CC (MDC 17)
  • MS-DRG 828 — MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASMS WITH MAJOR O.R. PROCEDURES WITHOUT CC/MCC (MDC 17)
  • MS-DRG 829 — MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASMS WITH OTHER PROCEDURES WITH CC/MCC (MDC 17)
  • MS-DRG 830 — MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASMS WITH OTHER PROCEDURES WITHOUT CC/MCC (MDC 17)
  • MS-DRG 843 — OTHER MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASTIC DIAGNOSES WITH MCC (MDC 17)
  • MS-DRG 844 — OTHER MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASTIC DIAGNOSES WITH CC (MDC 17)
  • MS-DRG 845 — OTHER MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASTIC DIAGNOSES WITHOUT CC/MCC (MDC 17)

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 D09.9 in the official ICD-10-CM tabular list, quoted as published.

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

Notes without a marker are published on D09.9 itself; “inherited from” names the category or block whose note applies here.

Includes

Conditions the official ICD-10-CM tabular list includes under this code.

  • Bowen's disease
  • erythroplasia
  • grade III intraepithelial neoplasia
  • Queyrat's erythroplasia

Source: inherited from D00-D09

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 D09

Coder workflow for D09.9

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

Before you code D09.9

  1. Unspecified does not mean incorrect. When the record gives no greater specificity, D09.9 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).

    ReviewD09.0, D09.2, D09.3, D09.8

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

  2. Confirm the documented site and behavior (this code’s block classifies in situ 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 →

  3. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with D09.9. 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 record document the detail a more specific sibling code needs?
    Yes → Review the specific siblings in this subcategory.
    No → Continue — D09.9 is appropriate when the documentation goes no further.

    ReviewD09.0, D09.2, D09.3, D09.8

  2. Does the documentation support a condition named in D09.9’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 D09.9. 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.
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

  • Excludes1 — check before selecting D09.9(1 note)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with D09.9: 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

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).

ReviewD09.0, D09.2, D09.3, D09.8

Documentation: Both the condition D09.9 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.

Code Overview

Carcinoma in situ, unspecified is a billable ICD-10-CM diagnosis code (D09.9).

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 — Ca in situ
  • Neoplasm, neoplastic, unknown site or unspecified — Ca in situ

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 D09.9 or its code family, from the CMS Table of Neoplasms and the CMS Table of Neoplasms (site match derived from the code title).

Referenced by 5 Same-site neoplasm codes: C79.9 — Secondary malignant neoplasm of unspecified siteCompare D09.9 vs C79.9 →, C80.1 — Malignant (primary) neoplasm, unspecifiedCompare D09.9 vs C80.1 →, D36.9 — Benign neoplasm, unspecified siteCompare D09.9 vs D36.9 →, D48.9 — Neoplasm of uncertain behavior, unspecifiedCompare D09.9 vs D48.9 →, D49.9 — Neoplasm of unspecified behavior of unspecified siteCompare D09.9 vs D49.9 →.

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

Referenced by 1 Screening & history code: Z85.819 — Personal history of malignant neoplasm of unspecified site of lip, oral cavity, and pharynxCompare D09.9 vs Z85.819 →.

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

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 8 MS-DRGs: DRG 826 (MDC 17), DRG 827 (MDC 17), DRG 828 (MDC 17), DRG 829 (MDC 17), DRG 830 (MDC 17), DRG 843 (MDC 17), DRG 844 (MDC 17), DRG 845 (MDC 17).

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

Clinical classification (AHRQ CCSR):NEO071 — Malignant neoplasm, unspecified (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 (Malignant neoplasm, unspecified).

C80.0 — Disseminated malignant neoplasm, unspecified, C80.1 — Malignant (primary) neoplasm, unspecified, C80.2 — Malignant neoplasm associated with transplanted organ, Z19.1 — Hormone sensitive malignancy status, Z19.2 — Hormone resistant malignancy status

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.

Iron Panel

Contextual Map

Every relationship of D09.9 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.

Hierarchy

Same site

Referenced by Same-site neoplasm codes

Referenced by Screening & history codes MedCoder-derived

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

  • MDC 17 — Myeloproliferative Diseases and Disorders, Poorly Differentiated Neoplasms[MDC crossing]: “Myeloproliferative Diseases and Disorders, Poorly Differentiated Neoplasms — 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. 4,735 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027

Neoplasm sites

  • Neoplasm, neoplastic — Neoplasm, neoplastic — Ca in situ [Neoplasm table]: “Neoplasm, neoplastic (Ca in situ)”— CMS Table of Neoplasms · icd10cm-fy2026
  • Neoplasm, neoplastic, unknown site or unspecified — Neoplasm, neoplastic, unknown site or unspecified — Ca in situ [Neoplasm table]: “Neoplasm, neoplastic, unknown site or unspecified (Ca in situ)”— CMS Table of Neoplasms · 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 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 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. "D09.9 — Carcinoma in situ, unspecified." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/d09.9-carcinoma-in-situ-unspecified

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Carcinoma in situ, unspecified

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 D09.9 in its code family, with their registry titles.

View all codes in the D09 family