2027 ICD-10-CM Diagnosis Code S86.309SUnspecified injury of muscle(s) and tendon(s) of peroneal muscle group at lower leg level, unspecified leg, sequela

ICD-10-CM Codes›S00–T88›S80-S89›S86

ICD-10-CM S86.309S
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

S86.309S is a billable ICD-10-CM diagnosis code for unspecified injury of muscle(s) and tendon(s) of peroneal muscle group at lower leg level, unspecified leg, 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 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 913 through 914. The code is exempt from POA reporting. Coders also document this condition as injury of multiple muscles and tendons at lower leg level. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury, sequela.

Code Identity

ICD-10-CM Code
S86.309S
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified injury of muscle(s) and tendon(s) of peroneal muscle group at lower leg level, unspecified leg, sequela
Short Description
Unsp inj musc/tend peroneal grp at low leg lev,unsp leg,sqla
Parent Code
S86.309
Unspecified injury of muscle(s) and tendon(s) of peroneal muscle group at lower leg level, unspecified leg

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS80-S89Injuries to the knee and lower leg
CategoryS86Injury of muscle, fascia and tendon at lower leg level
This CodeS86.309SUnspecified injury of muscle(s) and tendon(s) of peroneal muscle group at lower leg level, unspecified leg, sequela

Present on Admission (POA)Billing

S86.309S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review the other POA exempt codes in Injuries to the knee and lower leg (S80-S89).

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Injury of multiple muscles and tendons at lower leg level
  • Injury of muscle of peroneal muscle group at lower leg level

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Injury of muscle, fascia and tendon at lower leg level (S86). 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 S86.309S: its own notes plus those printed at S86, block S80-S89, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.

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 S86 Injury of muscle, fascia and tendon at lower leg level applies to 216 codes
  • injury of muscle, fascia and tendon at ankle (S96.-)
  • injury of patellar ligament (tendon) (S76.1-)
  • sprain of joints and ligaments of knee (S83.-)
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 S86 Injury of muscle, fascia and tendon at lower leg level applies to 216 codes
  • any associated open wound (S81.-)

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 S86 Injury of muscle, fascia and tendon at lower leg level applies to 216 codes
  • The appropriate 7th character is to be added to each code from category S86
Values for category S86 Encounter: Initial, Subsequent, Sequela
  • Ainitial encounter
  • Dsubsequent encounter
  • Ssequela this code

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

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name S86.309S, its category, or a range that includes it.

Excludes2 2

These codes carry an Excludes2 note naming S86.309S: its condition is not part of those codes, and both may be reported when the patient has both.

  • S76 Injury of muscle, fascia and tendon at hip and thigh level
    injury of muscle, fascia and tendon at lower leg level (S86) names S86, which includes this code
  • S83 Dislocation and sprain of joints and ligaments of knee
    strain of muscle, fascia and tendon of lower leg (S86.-) names S86.-, which includes this code

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

Leg Injuries and Disorders

Your legs are made up of bones, blood vessels, muscles, and other connective tissue. They are important for motion and standing. Playing sports, running, falling, or having an accident can damage your legs. Common leg injuries include sprains and strains, joint dislocations, and fractures (broken bones).

Read the full article at MedlinePlus

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

Convert S86.309S to ICD-9-CMHistory

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

ICD-9-CM
908.9 Late effect injury NOS
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 S86.309SOverview

Is S86.309S a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report unspecified injury of muscle(s) and tendon(s) of peroneal muscle group at lower leg level, unspecified leg, sequela on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character S in S86.309S mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the unspecified injury of muscle(s) and tendon(s) of peroneal muscle group at lower leg level, unspecified leg itself has resolved, not the original event.

What MS-DRG does S86.309S group to?

When unspecified injury of muscle(s) and tendon(s) of peroneal muscle group at lower leg level, unspecified leg, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 914, 913, with relative weights from 0.9281 to 1.5448 depending on complications. Higher weights mean higher Medicare reimbursement.

Is S86.309S 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 unspecified injury of muscle(s) and tendon(s) of peroneal muscle group at lower leg level, unspecified leg, sequela on inpatient claims. The code appears in the Injuries to the knee and lower leg (S80-S89) range of the CMS exempt list.

What is the ICD-9 equivalent of S86.309S?

Under the General Equivalence Mappings, unspecified injury of muscle(s) and tendon(s) of peroneal muscle group at lower leg level, unspecified leg, sequela converts to ICD-9-CM 908.9 (late effect injury NOS). The mapping is approximate, so confirm the match fits the documentation.