C20 — Malignant neoplasm of rectum

C20

ICD-10 Chapter 2: Neoplasms — illustrative image — Chapter 2: Neoplasms (C00–D49) — illustrative image

What this code means

Cancer that starts in the rectum, the last section of the large bowel.

Also called: rectal cancer.

When this code is used

Used for malignant neoplasm of the rectum.

Where it sits in ICD-10-CM

Code C20 belongs to Chapter 2: Neoplasms, which covers codes C00–D49 in the FY2027 ICD-10-CM tabular list. The official description above is copied verbatim from the CDC/NCHS FY2027 code file.

Learn more about this condition

Condition guide: Cancer

Related anatomy

Colon

Watch: related videos

▶ WatchRobotic total mesorectal excision for treatment of rectal cancer ▶ WatchLaparoscopic anterior resection for rectal cancer ▶ WatchTypical rectal cancer endoscopy

Frequently asked questions

What is ICD-10-CM code C20?

C20 is the ICD-10-CM diagnosis code for “Malignant neoplasm of rectum”. Cancer that starts in the rectum, the last section of the large bowel.

When is code C20 used?

Used for malignant neoplasm of the rectum. It belongs to Chapter 2 of ICD-10-CM (Neoplasms).

This guide explains ICD-10-CM codes in plain language for patients, students and other readers. It is educational information only — not coding, billing or medical advice. The code recorded for any real encounter is assigned from the full clinical documentation by the treating team and qualified coders, and only they can decide which code fits a specific case.