ICD-10-CM 2027 diagnosis code

C17Malignant neoplasm of small intestine

Not billable — use a more specific code

C17 is a header code, so it can't be reported by itself. Choose one of the 6 more specific codes beneath it.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About C17

C17 is the ICD-10-CM diagnosis code for malignant neoplasm of small intestine. It belongs to block C15-C26 (malignant neoplasms of digestive organs) and chapter 2 (neoplasms). It is a header code, so it can't be reported by itself; one of its 6 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: C17.0 (duodenum), C17.1 (jejunum), C17.2 (ileum), C17.3 (malignant), C17.8 (intestine) and C17.9 (unspecified).

Don't report C17 together with the conditions in its Excludes1 note: malignant carcinoid tumors of the small intestine (C7A.01).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Specific codes under C17

Coding notes

Excludes1Not coded here — never report together with this code

malignant carcinoid tumors of the small intestine (C7A.01)

Notes that apply from higher levels

Instructions written at a parent level also apply to C17.

Broader instructions also apply from C15-C26 Malignant neoplasms of digestive organs and Chapter 2: Neoplasms.

Code history

2016
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2021
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2023
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2025
2026
2027

FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
No changes since FY2016.

Common questions about C17

Is C17 billable?: No. C17 is a header code. Report one of its more specific subcodes instead.