2026 ICD-10-CM Diagnosis Code S80.859ASuperficial foreign body, unspecified lower leg, initial encounter

ICD-10-CM CodesS00–T88S80-S89S80

ICD-10-CM S80.859A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S80.859A is a billable ICD-10-CM diagnosis code for superficial foreign body, unspecified lower leg, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. 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, 963 through 965. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Superficial injury; contusion, initial encounter.

Code Identity

ICD-10-CM Code
S80.859A
Billable Status
Yes — Valid for Submission
Code Describes
Superficial foreign body, unspecified lower leg, initial encounter
Short Description
Superficial foreign body, unspecified lower leg, init encntr
Parent Code
Superficial foreign body, unspecified lower leg

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS80-S89Injuries to the knee and lower leg
CategoryS80Superficial injury of knee and lower leg
This CodeS80.859ASuperficial foreign body, unspecified lower leg, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Foreign body in skin of calf
  • Foreign body in skin of lower leg
  • Foreign body in skin of lower leg with infection
  • Foreign body in skin of lower limb
  • Foreign body in skin of shin
  • Splinter in lower leg
  • Splinter in lower leg with infection
  • Splinter in lower limb with infection
  • Wood splinter in calf
  • Wood splinter in lower leg

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Superficial injury of knee and lower leg (S80). 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 INJ017
Superficial injury; contusion, initial encounter
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 S80.859A to ICD-9-CMHistory

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

ICD-9-CM
916.6 Foreign body hip/leg
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 S80.859AOverview

Is S80.859A (Superficial foreign body, unspecified lower leg) a billable code?

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

What does the 7th character A in S80.859A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for superficial foreign body, unspecified lower leg, such as an emergency visit or first evaluation.

What MS-DRG does S80.859A group to?

When superficial foreign body, unspecified lower leg, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 604, 605, 963, 964, 965, with relative weights from 0.9160 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of S80.859A?

Under the General Equivalence Mappings, superficial foreign body, unspecified lower leg, initial encounter converts to ICD-9-CM 916.6 (foreign body hip/leg). 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.