2026 ICD-10-CM Diagnosis Code D02.4Carcinoma in situ of respiratory system, unspecified

ICD-10-CM CodesC00–D49D00-D09D02

ICD-10-CM D02.4
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

D02.4 is a billable ICD-10-CM diagnosis code for carcinoma in situ of respiratory system, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 180 through 182. Coders also document this condition as carcinoma in situ of respiratory and intrathoracic organ. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Respiratory cancers.

Code Identity

ICD-10-CM Code
D02.4
Billable Status
Yes — Valid for Submission
Code Describes
Carcinoma in situ of respiratory system, unspecified
Short Description
Carcinoma in situ of respiratory system, unspecified
Same as the full description in the CMS dataset.
Parent Code
Carcinoma in situ of middle ear and respiratory system

Code Classification

ChapterC00–D49Neoplasms
SectionD00-D09In situ neoplasms
CategoryD02Carcinoma in situ of middle ear and respiratory system
This CodeD02.4Carcinoma in situ of respiratory system, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Carcinoma in situ of respiratory and intrathoracic organ
  • Carcinoma in situ of respiratory system
  • Carcinoma in situ of respiratory tract
  • Carcinoma in situ of upper respiratory tract

Clinical ClassificationClinical

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

CCSR NEO022
Respiratory cancers
Default principal diagnosis: inpatient Yes · outpatient Yes

Table of NeoplasmsClinical

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

SiteMalig.
Primary
Malig.
Secondary
Ca
in situ
BenignUncertainUnspec.
respiratoryC39.9C78.30D02.4D14.4D38.6D49.1
respiratory organs or system NECC39.9C78.30D02.4D14.4D38.6D49.1
respiratory tract NECC39.9C78.30D02.4D14.4D38.5D49.1
respiratory tract NEC upperC39.0C78.30D02.4D14.4D38.5D49.1

Patient EducationClinical

Cancer

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Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert D02.4 to ICD-9-CMHistory

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

ICD-9-CM
231.9 Ca in situ resp sys 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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About D02.4Overview

Is D02.4 (Carcinoma in situ of middle ear and respiratory system) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report carcinoma in situ of respiratory system, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does D02.4 group to?

When carcinoma in situ of respiratory system, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 180, 181, 182, with relative weights from 0.7440 to 1.7660 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of D02.4?

Under the General Equivalence Mappings, carcinoma in situ of respiratory system, unspecified converts to ICD-9-CM 231.9 (ca in situ resp sys NOS). The mapping is a direct match.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.