2026 ICD-10-CM Diagnosis Code S86.029ALaceration of unspecified Achilles tendon, initial encounter

ICD-10-CM Codes›S00–T88›S80-S89›S86

ICD-10-CM S86.029A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S86.029A is a billable ICD-10-CM diagnosis code for laceration of unspecified Achilles tendon, 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 564 through 566, 963 through 965. The code is flagged as an unspecified code, since codes identifying laterality exist in the same family. Coders also document this condition as laceration of Achilles tendon. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Open wounds to limbs, initial encounter.

Code Identity

ICD-10-CM Code
S86.029A
Billable Status
Yes — Valid for Submission
Code Describes
Laceration of unspecified Achilles tendon, initial encounter
Short Description
Laceration of unspecified Achilles tendon, initial encounter
Same as the full description in the CMS dataset.
Parent Code
S86.029
Laceration of unspecified Achilles tendon

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 CodeS86.029ALaceration of unspecified Achilles tendon, initial encounter

Code EditsBilling

Medicare Code Editor checks that affect claim validity for S86.029A.

Unspecified codes
Unspecified codes exist in the ICD-10-CM classification for circumstances when documentation in the medical record does not provide the level of detail needed to support reporting a more specific code. However, in the inpatient setting, there should generally be very limited and rare circumstances for which the laterality (right, left, bilateral) of a condition is unable to be documented and reported. The following pages contain the list of unspecified ICD-10-CM diagnosis codes for which there is a more specific code to identify laterality (right, left, bilateral) within that code family.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Laceration of Achilles tendon
  • Laceration of calf
  • Laceration of tendon of lower leg

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 2026, published by CMS and the National Center for Health Statistics.

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

Heel Injuries and Disorders

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Read the full article at MedlinePlus

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

Convert S86.029A to ICD-9-CMHistory

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

ICD-9-CM
891.2 Opn wnd knee/leg w tendn
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 S86.029AOverview

Is S86.029A (Laceration of unspecified Achilles tendon) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report laceration of unspecified Achilles tendon, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in S86.029A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for laceration of unspecified Achilles tendon, such as an emergency visit or first evaluation.

What MS-DRG does S86.029A group to?

When laceration of unspecified Achilles tendon, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 564, 565, 566, 963, 964, 965, with relative weights from 0.7493 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of S86.029A?

Under the General Equivalence Mappings, laceration of unspecified Achilles tendon, initial encounter converts to ICD-9-CM 891.2 (opn wnd knee/leg w tendn). 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.