2027 ICD-10-CM Diagnosis Code D09.9Carcinoma in situ, unspecified

ICD-10-CM Codes›C00–D49›D00-D09›D09

ICD-10-CM D09.9
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

D09.9 is a billable ICD-10-CM diagnosis code for carcinoma in situ, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 826 through 830, 843 through 845. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Malignant neoplasm, unspecified.

Code Identity

ICD-10-CM Code
D09.9
Billable Status
Yes — Valid for Submission
Code Describes
Carcinoma in situ, unspecified
Short Description
Carcinoma in situ, unspecified
Same as the full description in the CMS dataset.
Parent Code
D09
Carcinoma in situ of other and unspecified sites

Code Classification

ChapterC00–D49Neoplasms
SectionD00-D09In situ neoplasms
CategoryD09Carcinoma in situ of other and unspecified sites
This CodeD09.9Carcinoma in situ, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Adenocarcinoma in situ in villous adenoma
  • Carcinoma in situ
  • Common bile duct surgical margin, involved by tumor
  • Intraepithelial squamous cell carcinoma
  • Squamous cell carcinoma in situ
  • Surgical bile duct margin involved by carcinoma in situ
  • Surgical bile duct margin uninvolved by carcinoma in situ
  • Surgical bronchial margin involved by squamous cell carcinoma in situ
  • Surgical bronchial margin involved by tumor
  • Surgical common bile duct margin involved by in situ carcinoma
  • Surgical common bile duct margin uninvolved by in situ carcinoma
  • Surgical cystic duct margin involved by in situ carcinoma
  • Surgical cystic duct margin uninvolved by in situ carcinoma
  • Surgical deep margin involved by in situ carcinoma
  • Surgical deep margin uninvolved by in situ carcinoma
  • Surgical distal margin involved by in situ carcinoma
  • Surgical distal margin involved by in situ carcinoma/adenoma
  • Surgical distal margin involved by tumor
  • Surgical distal margin uninvolved by in situ carcinoma
  • Surgical distal margin uninvolved by in situ carcinoma/adenoma
  • Surgical distal mucosal margin involved by in situ carcinoma
  • Surgical distal mucosal margin uninvolved by in situ carcinoma
  • Surgical ductal margin uninvolved by in situ carcinoma
  • Surgical lateral margin involved by in situ carcinoma
  • Surgical lateral margin involved by in situ carcinoma/adenoma
  • Surgical lateral margin uninvolved by in situ carcinoma
  • Surgical lateral margin involved by tumor
  • Surgical margin involved by in situ carcinoma
  • Surgical margin involved by in situ carcinoma/adenoma
  • Surgical margin uninvolved by in situ carcinoma
  • Surgical margin uninvolved by in situ carcinoma/adenoma
  • Surgical mucosal margin involved by in situ carcinoma
  • Surgical mucosal margin uninvolved by in situ carcinoma
  • Surgical pancreatic duct margin involved by in situ carcinoma
  • Surgical pancreatic duct margin uninvolved by in situ carcinoma
  • Surgical pancreatic parenchymal margin involved by in situ carcinoma
  • Surgical parenchymal margin finding
  • Surgical proximal margin involved by in situ carcinoma
  • Surgical proximal margin involved by in situ carcinoma/adenoma
  • Surgical proximal margin uninvolved by in situ carcinoma
  • Surgical proximal margin uninvolved by in situ carcinoma/adenoma
  • Surgical proximal mucosal margin involved by in situ carcinoma
  • Surgical proximal mucosal margin uninvolved by in situ carcinoma

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to D09.9: its own notes plus those printed at D09, block D00-D09, and Chapter 2. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Block D00-D09 In situ neoplasms applies to 106 codes
  • Bowen's disease
  • erythroplasia
  • grade III intraepithelial neoplasia
  • Queyrat's erythroplasia

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From D09 Carcinoma in situ of other and unspecified sites applies to 9 codes

Notes

General instructions on how these codes are used.

From Chapter 2 (C00-D49) Neoplasms applies to 1,730 codes
  • Functional activity
  • All neoplasms are classified in this chapter, whether they are functionally active or not. An additional code from Chapter 4 may be used, to identify functional activity associated with any neoplasm.
  • Morphology [Histology]
  • Chapter 2 classifies neoplasms primarily by site (topography), with broad groupings for behavior, malignant, in situ, benign, etc. The Table of Neoplasms should be used to identify the correct topography code. In a few cases, such as for malignant melanoma and certain neuroendocrine tumors, the morphology (histologic type) is included in the category and codes.
  • Primary malignant neoplasms overlapping site boundaries
  • A primary malignant neoplasm that overlaps two or more contiguous (next to each other) sites should be classified to the subcategory/code .8 ('overlapping lesion'), unless the combination is specifically indexed elsewhere. For multiple neoplasms of the same site that are not contiguous, such as tumors in different quadrants of the same breast, codes for each site should be assigned.
  • Malignant neoplasm of ectopic tissue
  • Malignant neoplasms of ectopic tissue are to be coded to the site mentioned, e.g., ectopic pancreatic malignant neoplasms are coded to pancreas, unspecified (C25.9).

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name D09.9, its category, or a range that includes it.

Applicable To 1

These notes mention D09.9.

  • Z86.008 Personal history of in-situ neoplasm of other site
    Conditions classifiable to D09 names D09, which includes this code

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NEO071
Malignant neoplasm, unspecified
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Carcinoma in Situ

    a lesion with cytological characteristics associated with invasive carcinoma but the tumor cells are confined to the epithelium of origin, without invasion of the basement membrane.

Table of NeoplasmsClinical

Anatomical sites in the Table of Neoplasms that reference this code family.

SiteMalig.
Primary		Malig.
Secondary		Ca
in situ		BenignUncertainUnspec.
Neoplasm, neoplasticC80.1C79.9D09.9D36.9D48.9D49.9
unknown site or unspecifiedC80.1C79.9D09.9D36.9D48.9D49.9

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Convert D09.9 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
234.9 Ca in situ NOS
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About D09.9Overview

What is the ICD-10 code for carcinoma in situ, unspecified?

The ICD-10-CM code for carcinoma in situ, unspecified is D09.9 (sometimes written as D099). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is D09.9 (Carcinoma in situ of other and unspecified sites) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report carcinoma in situ, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does D09.9 group to?

When carcinoma in situ, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 844, 827, 829, 843, 828, 826, 830, 845, with relative weights from 0.8443 to 4.7560 depending on complications. Higher weights mean higher Medicare reimbursement.

Can D09.9 be reported with a code from D03?

Not as a rule. The Excludes1 note at D09, which applies to D09.9, lists "melanoma in situ (D03.-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

What is the ICD-9 equivalent of D09.9?

Under the General Equivalence Mappings, carcinoma in situ, unspecified converts to ICD-9-CM 234.9 (ca in situ NOS). The mapping is a direct match.