2027 ICD-10-CM Diagnosis Code S81.821ALaceration with foreign body, right lower leg, initial encounter

ICD-10-CM Codes›S00–T88›S80-S89›S81

ICD-10-CM S81.821A
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

S81.821A is a billable ICD-10-CM diagnosis code for laceration with foreign body, right 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 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 913 through 914, 963 through 965. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Open wounds to limbs, initial encounter.

Code Identity

ICD-10-CM Code
S81.821A
Billable Status
Yes — Valid for Submission
Code Describes
Laceration with foreign body, right lower leg, initial encounter
Short Description
Laceration with foreign body, right lower leg, init encntr
Parent Code
S81.821
Laceration with foreign body, right lower leg

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS80-S89Injuries to the knee and lower leg
CategoryS81Open wound of knee and lower leg
This CodeS81.821ALaceration with foreign body, right lower leg, initial encounter

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Open wound of knee and lower leg (S81). 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 2027, published by CMS and the National Center for Health Statistics.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to S81.821A: its own notes plus those printed at S81, block S80-S89, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From S81 Open wound of knee and lower leg applies to 108 codes
  • open fracture of knee and lower leg (S82.-)
  • traumatic amputation of lower leg (S88.-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From S81 Open wound of knee and lower leg applies to 108 codes
  • open wound of ankle and foot (S91.-)
From Block S80-S89 Injuries to the knee and lower leg applies to 4,680 codes
  • burns and corrosions (T20-T32)
  • frostbite (T33-T34)
  • injuries of ankle and foot, except fracture of ankle and malleolus (S90-S99)
  • insect bite or sting, venomous (T63.4)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • code to identify any retained foreign body, if applicable (Z18.-)

Code Also

A second code may be needed to fully describe the condition; the note gives no sequencing direction.

From S81 Open wound of knee and lower leg applies to 108 codes
  • any associated wound infection

Notes

General instructions on how these codes are used.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
  • The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.

7th Character

Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.

From S81 Open wound of knee and lower leg applies to 108 codes
  • The appropriate 7th character is to be added to each code from category S81
Values for category S81 Encounter: Initial, Subsequent, Sequela
  • Ainitial encounter this code
  • Dsubsequent encounter
  • Ssequela

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name S81.821A, its category, or a range that includes it.

Excludes2 1

These codes carry an Excludes2 note naming S81.821A: its condition is not part of those codes, and both may be reported when the patient has both.

  • S71 Open wound of hip and thigh
    open wound of knee and lower leg (S81.-) names S81.-, which includes this code

Code Also 3

These codes say S81.821A may also be needed to fully describe the condition. The note gives no sequencing direction.

  • S84 Injury of nerves at lower leg level
    any associated open wound (S81.-) names S81.-, which includes this code
  • S85 Injury of blood vessels at lower leg level
    any associated open wound (S81.-) names S81.-, which includes this code
  • S86 Injury of muscle, fascia and tendon at lower leg level
    any associated open wound (S81.-) names S81.-, which includes this code

Clinical ClassificationClinical

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

CCSR INJ012
Open wounds to limbs, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Wounds and Injuries

An injury is damage to your body. It is a general term that refers to harm caused by accidents, falls, hits, weapons, and more. In the U.S., millions of people injure themselves every year. These injuries range from minor to life-threatening.

Read the full article at MedlinePlus

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

Convert S81.821A to ICD-9-CMHistory

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

ICD-9-CM
891.1 Open wnd knee/leg-compl
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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About S81.821AOverview

What is the ICD-10 code for laceration with foreign body, right lower leg, initial encounter?

The ICD-10-CM code for laceration with foreign body, right lower leg, initial encounter is S81.821A (sometimes written as S81821A). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is S81.821A (Laceration with foreign body, right lower leg) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report laceration with foreign body, right lower leg, initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character A in S81.821A mean?

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

What MS-DRG does S81.821A group to?

When laceration with foreign body, right lower leg, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 964, 965, 914, 913, 963, with relative weights from 0.9281 to 2.6361 depending on complications. Higher weights mean higher Medicare reimbursement.

Can S81.821A be reported with a code from S82?

Not as a rule. The Excludes1 note at S81, which applies to S81.821A, lists "open fracture of knee and lower leg (S82.-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).