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ICD-10 Code C80.1: Malignant (primary) neoplasm, unspecified

C80.1 is a billable ICD-10 diagnosis code used to classify Malignant (primary) neoplasm, unspecified 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).

Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026

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 (primary) neoplasm, unspecified 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
C76-C80Malignant neoplasms of ill-defined, other secondary and unspecified sites
category
C80Malignant neoplasm without specification of site
currentC80

Official coding notes

Inclusion terms
  • Cancer NOS
  • Cancer unspecified site (primary)
  • Carcinoma unspecified site (primary)
  • Malignancy unspecified site (primary)
Excludes1 (do not code together)
  • secondary malignant neoplasm of unspecified site (C79.9)

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 0543Uhigh
ONCOLOGY (SOLID TUMOR), NEXT-GENERATION SEQUENCING OF DNA FROM FORMALIN-FIXED PARAFFIN-EMBEDDED (FFPE) TISSUE OF 517 GENES, INTERROGATION FOR SINGLE-NUCLEOTIDE VARIANTS, MULTI-NUCLEOTIDE VARIANTS, INSERTIONS AND DELETIONS FROM DNA, FUSIONS IN 24 GENES AND SPLICE VARIANTS IN 1 GENE FROM RNA, AND TUMOR MUTATION BURDEN
Source: CMS coverage guidance
CPT 0329Uhigh
ONCOLOGY (NEOPLASIA), EXOME AND TRANSCRIPTOME SEQUENCE ANALYSIS FOR SEQUENCE VARIANTS, GENE COPY NUMBER AMPLIFICATIONS AND DELETIONS, GENE REARRANGEMENTS, MICROSATELLITE INSTABILITY AND TUMOR MUTATIONAL BURDEN UTILIZING DNA AND RNA FROM TUMOR WITH DNA FROM NORMAL BLOOD OR SALIVA FOR SUBTRACTION, REPORT OF CLINICALLY SIGNIFICANT MUTATION(S) WITH THERAPY ASSOCIATIONS
Source: CMS coverage guidance
CPT 0250Uhigh
ONCOLOGY (SOLID ORGAN NEOPLASM), TARGETED GENOMIC SEQUENCE DNA ANALYSIS OF 505 GENES, INTERROGATION FOR SOMATIC ALTERATIONS (SNVS [SINGLE NUCLEOTIDE VARIANT], SMALL INSERTIONS AND DELETIONS, ONE AMPLIFICATION, AND FOUR TRANSLOCATIONS), MICROSATELLITE INSTABILITY AND TUMOR-MUTATION BURDEN
Source: CMS coverage guidance
CPT 0244Uhigh
ONCOLOGY (SOLID ORGAN), DNA, COMPREHENSIVE GENOMIC PROFILING, 257 GENES, INTERROGATION FOR SINGLE-NUCLEOTIDE VARIANTS, INSERTIONS/DELETIONS, COPY NUMBER ALTERATIONS, GENE REARRANGEMENTS, TUMOR-MUTATIONAL BURDEN AND MICROSATELLITE INSTABILITY, UTILIZING FORMALIN-FIXED PARAFFIN-EMBEDDED TUMOR TISSUE
Source: CMS coverage guidance

Coding guidelines

Common synonyms

Malignant (primary) neoplasm, unspecifiedMalignant (primary) neoplasmMalignantMalignant primary neoplasm, unspecified

Frequently asked questions

Code details

CodeC80.1
SystemICD10
Display nameMalignant (primary) neoplasm, unspecified
ChapterNeoplasms (C00-D49)
BlockMalignant neoplasms of ill-defined, other secondary and unspecified sites

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
CancerCarcinoma(malignant)MalignancySarcomatosisTumorTumorTumorTumorTumorTumorTumor
See also
Neoplasm, malignant, by site

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.

ICD-10 Code C80.1 for Malignant (primary) neoplasm, unspecified | HealthAssure