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

ICD-10-CM Code View

HCC Buddy Code Card

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FY 2026 Apr update / Neoplasms (C00-D49) / In situ neoplasms (D00-D09)

D09.9

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Carcinoma in situ, unspecified

Abnormal cell growth that has not yet become invasive cancer, but the specific location in the body is not documented or specified.

CMS-HCC V28

0

0

RAF 0

CMS-HCC V24

0

0

RAF 0

ACA/HHS

0

0

RAF 0

ESRD/PACE

0

0

RAF 0

RXHCC

0

0

RAF 0

Code Trumping

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Code Book Path

Official
D09Carcinoma in situ of other and unspecified sites
D09.9Carcinoma in situ, unspecified

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for D09.9 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for D09.9 in this effective period.

Related Child Codes

Official
D09.0Carcinoma in situ of bladder
D09.1Carcinoma in situ of other and unspecified urinary organs
D09.2Carcinoma in situ of eye
D09.3Carcinoma in situ of thyroid and other endocrine glands
D09.8Carcinoma in situ of other specified sites

Includes

Official

ICD-10-CM does not list Includes notes for D09.9 in this effective period.

Excludes 1

Official
  • melanoma in situ (D03.-)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for D09.9 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for D09.9 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for D09.9 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance
This is the least specific carcinoma in situ code; query the provider if the anatomical site can be determined for more accurate coding
Use only when the site of carcinoma in situ is truly unspecified or unknown

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is D09.9 an HCC code?

No. D09.9 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.

Coder workflow notes

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This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).

What This Code Means

D09.9 is the ICD-10-CM diagnosis code for carcinoma in situ, unspecified. Abnormal cell growth that has not yet become invasive cancer, but the specific location in the body is not documented or specified. D09.9 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering in situ neoplasms (d00-d09).

D09.9 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

This is the least specific carcinoma in situ code; query the provider if the anatomical site can be determined for more accurate coding.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for D09.9 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

  • This is the least specific carcinoma in situ code; query the provider if the anatomical site can be determined for more accurate coding
  • Use only when the site of carcinoma in situ is truly unspecified or unknown

Child Codes

Code Hierarchy

Work D09.9 in HCC Buddy

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