2026 ICD-10-CM Diagnosis Code S40.859SSuperficial foreign body of unspecified upper arm, sequela

ICD-10-CM Codes›S00–T88›S40-S49›S40

ICD-10-CM S40.859S
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S40.859S is a billable ICD-10-CM diagnosis code for superficial foreign body of unspecified upper arm, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 604 through 605. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury, sequela.

Code Identity

ICD-10-CM Code
S40.859S
Billable Status
Yes — Valid for Submission
Code Describes
Superficial foreign body of unspecified upper arm, sequela
Short Description
Superficial foreign body of unspecified upper arm, sequela
Same as the full description in the CMS dataset.
Parent Code
S40.859
Superficial foreign body of unspecified upper arm

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS40-S49Injuries to the shoulder and upper arm
CategoryS40Superficial injury of shoulder and upper arm
This CodeS40.859SSuperficial foreign body of unspecified upper arm, sequela

Present on Admission (POA)Billing

S40.859S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Foreign body in skin of axilla
  • Foreign body in skin of axilla with infection
  • Foreign body in skin of upper arm
  • Foreign body in skin of upper arm with infection
  • Splinter in axilla
  • Splinter in axilla with infection
  • Splinter in shoulder
  • Splinter in shoulder with infection
  • Splinter in upper arm
  • Splinter in upper arm with infection
  • Superficial injury of axilla with infection
  • Wood splinter in axilla
  • Wood splinter in shoulder

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Superficial injury of shoulder and upper arm (S40). Use the following options for the applicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.

Clinical ClassificationClinical

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

CCSR INJ073
Injury, sequela
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Foreign Bodies

If you've ever gotten a splinter or had sand in your eye, you've had experience with a foreign body. A foreign body is something that is stuck inside you but isn't supposed to be there. You may inhale or swallow a foreign body, or you may get one from an injury to almost any part of your body.

Read the full article at MedlinePlus

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

Convert S40.859S to ICD-9-CMHistory

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

ICD-9-CM
906.2 Late eff superficial inj
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 S40.859SOverview

Is S40.859S (Superficial foreign body of unspecified upper arm) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report superficial foreign body of unspecified upper arm, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character S in S40.859S mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the superficial foreign body of unspecified upper arm itself has resolved, not the original event.

What MS-DRG does S40.859S group to?

When superficial foreign body of unspecified upper arm, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 604, 605, with relative weights from 0.9160 to 1.4721 depending on complications. Higher weights mean higher Medicare reimbursement.

Is S40.859S exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for superficial foreign body of unspecified upper arm, sequela on inpatient claims.

What is the ICD-9 equivalent of S40.859S?

Under the General Equivalence Mappings, superficial foreign body of unspecified upper arm, sequela converts to ICD-9-CM 906.2 (late eff superficial inj). 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.