2026 ICD-10-CM Diagnosis Code C44.621Squamous cell carcinoma of skin of unspecified upper limb, including shoulder

ICD-10-CM CodesC00–D49C43-C44C44

ICD-10-CM C44.621
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C44.621 is a billable ICD-10-CM diagnosis code for squamous cell carcinoma of skin of unspecified upper limb, including shoulder. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 606 through 607. Coders also document this condition as primary squamous cell carcinoma of upper limb. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Skin cancers - squamous cell carcinoma.

Code Identity

ICD-10-CM Code
C44.621
Billable Status
Yes — Valid for Submission
Code Describes
Squamous cell carcinoma of skin of unspecified upper limb, including shoulder
Short Description
Squamous cell carcinoma skin/ unsp upper limb, inc shoulder
Parent Code
Squamous cell carcinoma of skin of upper limb, including shoulder

Code Classification

ChapterC00–D49Neoplasms
SectionC43-C44Melanoma and other malignant neoplasms of skin
CategoryC44Other and unspecified malignant neoplasm of skin
This CodeC44.621Squamous cell carcinoma of skin of unspecified upper limb, including shoulder

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Primary squamous cell carcinoma of upper limb
  • Squamous cell carcinoma of hand
  • Squamous cell carcinoma of shoulder
  • Squamous cell carcinoma of upper extremity

Clinical ClassificationClinical

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

CCSR NEO027
Skin cancers - squamous cell carcinoma
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.
skin NOS limb NEC upper squamous cell carcinomaC44.62

Patient EducationClinical

Skin Cancer

Skin cancer is the most common form of cancer in the United States. The two most common types are basal cell cancer and squamous cell cancer. They usually form on the head, face, neck, hands, and arms. Another type of skin cancer, melanoma, is more dangerous but less common.

Read the full article at MedlinePlus

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

Convert C44.621 to ICD-9-CMHistory

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

ICD-9-CM
173.62 Squam cell ca skn up lmb
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 C44.621Overview

Is C44.621 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report squamous cell carcinoma of skin of unspecified upper limb, including shoulder on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does C44.621 group to?

When squamous cell carcinoma of skin of unspecified upper limb, including shoulder is the principal diagnosis on an inpatient stay, it groups to MS-DRG 606, 607, with relative weights from 0.9064 to 1.5132 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of C44.621?

Under the General Equivalence Mappings, squamous cell carcinoma of skin of unspecified upper limb, including shoulder converts to ICD-9-CM 173.62 (squam cell ca skn up lmb). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.