Colon Cancer ICD-10-CM Codes

Read this short guide and learn about colon cancer ICD codes you can use. Discover billing and clinical information here.

By Alex King on Aug 8, 2025.

Fact Checked by RJ Gumban.

Use Code

What ICD-10 Codes are Used for Colon Cancer

While there are no specific colon cancer ICD codes, you can use the following six codes for coding and billing:

C18.9 - Malignant neoplasm of colon, unspecified

This ICD-10 code is meant to be used on a person confirmed to have a malignant neoplasm in their colon. The specific location of the neoplasm in the colon is unspecified, however. It’s best to use a more specific ICD-10 code if the location has been determined.

C18.2 - Malignant neoplasm of ascending colon

This ICD-10 code is meant to be used on a person confirmed to have a malignant neoplasm in their ascending colon.

C18.4 - Malignant neoplasm of transverse colon

This ICD-10 code is meant to be used on a person confirmed to have a malignant neoplasm in their transverse colon.

C18.6 - Malignant neoplasm of descending colon

This ICD-10 code is meant to be used on a person confirmed to have a malignant neoplasm in their descending colon.

C18.7 - Malignant neoplasm of sigmoid colon

This ICD-10 code is meant to be used on a person confirmed to have a malignant neoplasm in their sigmoid colon.

C18.8 - Malignant neoplasm of overlapping sites of colon

This ICD-10 code is meant to be used on a person confirmed to have a malignant neoplasm in an overlapping site of the colon.

Are these colon cancer ICD codes billable?

Yes. All of the aforementioned colon cancer-related ICD-10 codes we listed above are valid and billable.

Clinical information

Colon cancer, also known as colorectal cancer, primarily begins as clumps of precancerous cells (polyps) on the colon's inner lining.
Common symptoms include changes in bowel habits, abdominal discomfort, fatigue, unexplained weight loss, and rectal bleeding.
Risk factors for developing colon cancer encompass age (over 50), African-American race, a personal or family history of colon polyps or colon cancer, inflammatory intestinal conditions, a low-fiber, high-fat diet, diabetes, obesity, smoking, alcohol, and a sedentary lifestyle.
To diagnose colon cancer, doctors may recommend tests like colonoscopy, blood tests, and imaging tests like CT scans.
Treatment options vary based on the stage of cancer and may include surgery, radiation therapy, chemotherapy, immunotherapy, or targeted drug therapy.
Early detection through routine screening can greatly reduce the risk of colon cancer.
It's typically recommended that individuals start screening at age 50, and even earlier for those with a high risk.

Synonyms include:

Carcinoma of colon
Carcinoma of colon, stage I
Carcinoma of colon, stage II
Carcinoma of colon, stage III
Carcinoma of colon, stage IV
Malignant tumor of colon
Malignant tumor of large intestine
Lymphoma of colon

Commonly asked questions

Yes. There is one that’s unbillable but we didn’t include that on the list above. It’s best not to use that because it’s invalid.

Colonoscopies are the best option. Other tests include, fecal tests, CBCs, CMPs, CT scans, X-rays, MRIs, PET scans, ultrasounds, and biopsies.

Healthcare professionals can treat colon cancer via polypectomy, partial colectomy, surgical resection with colostomy, chemotherapy, and targeted therapy.

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