2026 ICD-10-CM Diagnosis Code C40.10Malignant neoplasm of short bones of unspecified upper limb

ICD-10-CM CodesC00–D49C40-C41C40

ICD-10-CM C40.10
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C40.10 is a billable ICD-10-CM diagnosis code for malignant neoplasm of short bones of unspecified upper limb. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 542 through 544. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bone cancer.

Code Identity

ICD-10-CM Code
C40.10
Billable Status
Yes — Valid for Submission
Code Describes
Malignant neoplasm of short bones of unspecified upper limb
Short Description
Malignant neoplasm of short bones of unspecified upper limb
Same as the full description in the CMS dataset.
Parent Code
Malignant neoplasm of short bones of upper limb

Code Classification

ChapterC00–D49Neoplasms
SectionC40-C41Malignant neoplasms of bone and articular cartilage
CategoryC40Malignant neoplasm of bone and articular cartilage of limbs
This CodeC40.10Malignant neoplasm of short bones of unspecified upper limb

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Ewing sarcoma of bone structure of upper limb
  • Malignant neoplasm of carpal bone - capitate
  • Malignant neoplasm of carpal bone - hamate
  • Malignant neoplasm of carpal bone - lunate
  • Malignant neoplasm of carpal bone - pisiform
  • Malignant neoplasm of carpal bone - scaphoid
  • Malignant neoplasm of carpal bone - trapezium
  • Malignant neoplasm of carpal bone - trapezoid
  • Malignant neoplasm of carpal bone - triquetrum
  • Malignant neoplasm of carpal bones
  • Malignant neoplasm of fifth metacarpal bone
  • Malignant neoplasm of first metacarpal bone
  • Malignant neoplasm of fourth metacarpal bone
  • Malignant neoplasm of hand bones
  • Malignant neoplasm of metacarpal bones
  • Malignant neoplasm of phalanges of hand
  • Malignant neoplasm of second metacarpal bone
  • Malignant neoplasm of third metacarpal bone
  • Neoplasm of hamate bone
  • Neoplasm of lunate bone
  • Neoplasm of metacarpal bone
  • Neoplasm of phalanx of hand
  • Neoplasm of pisiform bone of wrist region
  • Neoplasm of scaphoid bone
  • Neoplasm of trapezium
  • Neoplasm of trapezoid bone
  • Primary Ewing sarcoma of bone of hand
  • Primary Ewing sarcoma of bone structure of upper limb
  • Primary malignant neoplasm of bone of hand
  • Primary malignant neoplasm of carpal bone
  • Primary malignant neoplasm of hamate bone
  • Primary malignant neoplasm of long bone of upper limb
  • Primary malignant neoplasm of lunate bone
  • Primary malignant neoplasm of metacarpal bone
  • Primary malignant neoplasm of phalanx of hand
  • Primary malignant neoplasm of pisiform bone of wrist region
  • Primary malignant neoplasm of scaphoid bone
  • Primary malignant neoplasm of short bone of upper limb
  • Primary malignant neoplasm of trapezium
  • Primary malignant neoplasm of trapezoid bone

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NEO023
Bone cancer
Default principal diagnosis: inpatient Yes · outpatient Yes

Table of NeoplasmsClinical

Anatomical sites in the Table of Neoplasms that reference this code family.

SiteMalig.
Primary
Malig.
Secondary
Ca
in situ
BenignUncertainUnspec.
bone (periosteum) carpus (any)C40.1C79.51D16.1
bone (periosteum) finger (any)C40.1C79.51D16.1
bone (periosteum) handC40.1C79.51D16.1
bone (periosteum) limb NEC upper (long bones) short bonesC40.1C79.51D16.1
bone (periosteum) metacarpus (any)C40.1C79.51D16.1
bone (periosteum) navicular handC40.1C79.51
bone (periosteum) phalanges handC40.1C79.51
bone (periosteum) scaphoid of handC40.1C79.51
bone (periosteum) thumbC40.1C79.51
bone (periosteum) trapeziumC40.1C79.51
bone (periosteum) trapezoidC40.1C79.51
bone (periosteum) unciformC40.1C79.51
bone (periosteum) wristC40.1C79.51
carpus (any bone)C40.1C79.51D16.1
metacarpus (any bone)C40.1C79.51D16.1
phalanges handC40.1C79.51D16.1

Patient EducationClinical

Bone Cancer

Cancer that starts in a bone is uncommon. Cancer that has spread to the bone from another part of the body is more common.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert C40.10 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
170.5 Mal neo bones wrist/hand
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About C40.10Overview

Is C40.10 (Malignant neoplasm of short bones of upper limb) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of short bones of unspecified upper limb on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does C40.10 group to?

When malignant neoplasm of short bones of unspecified upper limb is the principal diagnosis on an inpatient stay, it groups to MS-DRG 542, 543, 544, with relative weights from 0.7546 to 1.7665 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of C40.10?

Under the General Equivalence Mappings, malignant neoplasm of short bones of unspecified upper limb converts to ICD-9-CM 170.5 (mal neo bones wrist/hand). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.