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ICD10BillableValid for clinical use

ICD-10 Code C18.7: Malignant neoplasm of sigmoid colon

C18.7 is a billable ICD-10 diagnosis code used to classify Malignant neoplasm of sigmoid colon in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Neoplasms (C00-D49).

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Neoplasms (C00-D49).

When is it used?

  • May be used when a clinician documents malignant neoplasm of sigmoid colon in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.

Code hierarchy

chapter
2Neoplasms (C00-D49)
block
C00-C96Malignant neoplasms
block
C00-C75Malignant neoplasms, stated or presumed to be primary (of specified sites), and certain specified histologies, except neuroendocrine, and of lymphoid, hematopoietic and related tissue
block
C15-C26Malignant neoplasms of digestive organs
category
C18Malignant neoplasm of colon
currentC18

Official coding notes

Inclusion terms
  • Malignant neoplasm of sigmoid (flexure)
Excludes1 (do not code together)
  • malignant neoplasm of rectosigmoid junction (C19)

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Related specialists

OncologistGeneral Physician

Coverage-related procedures and services

CPT 81479high
UNLISTED MOLECULAR PATHOLOGY PROCEDURE
Source: CMS coverage guidance
CPT 81445high
SOLID ORGAN NEOPLASM, GENOMIC SEQUENCE ANALYSIS PANEL, 5-50 GENES, INTERROGATION FOR SEQUENCE VARIANTS AND COPY NUMBER VARIANTS OR REARRANGEMENTS, IF PERFORMED; DNA ANALYSIS OR COMBINED DNA AND RNA ANALYSIS
Source: CMS coverage guidance
CPT 44388high
COLONOSCOPY THROUGH STOMA; DIAGNOSTIC, INCLUDING COLLECTION OF SPECIMEN(S) BY BRUSHING OR WASHING, WHEN PERFORMED (SEPARATE PROCEDURE)
Source: CMS coverage guidance
CPT 44401high
COLONOSCOPY THROUGH STOMA; WITH ABLATION OF TUMOR(S), POLYP(S), OR OTHER LESION(S) (INCLUDES PRE-AND POST-DILATION AND GUIDE WIRE PASSAGE, WHEN PERFORMED)
Source: CMS coverage guidance
CPT 44389high
COLONOSCOPY THROUGH STOMA; WITH BIOPSY, SINGLE OR MULTIPLE
Source: CMS coverage guidance
CPT 44391high
COLONOSCOPY THROUGH STOMA; WITH CONTROL OF BLEEDING, ANY METHOD
Source: CMS coverage guidance

Coding guidelines

Compatibility

Legacy and official ICD code match exactly.
Legacy codes
C18.7

Common synonyms

Malignant neoplasm of sigmoid colon

Frequently asked questions

Code details

CodeC18.7
SystemICD10
Display nameMalignant neoplasm of sigmoid colon
ChapterNeoplasms (C00-D49)
BlockMalignant neoplasms of digestive organs

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.