2026 ICD-10-CM Diagnosis Code S88.029APartial traumatic amputation at knee level, unspecified lower leg, initial encounter

ICD-10-CM Codes›S00–T88›S80-S89›S88

ICD-10-CM S88.029A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S88.029A is a billable ICD-10-CM diagnosis code for partial traumatic amputation at knee level, 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 913 through 914, 963 through 965. The code is flagged as an unspecified code, since codes identifying laterality exist in the same family. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Amputation of a limb, initial encounter.

Code Identity

ICD-10-CM Code
S88.029A
Billable Status
Yes — Valid for Submission
Code Describes
Partial traumatic amputation at knee level, unspecified lower leg, initial encounter
Short Description
Partial traumatic amp at knee level, unsp lower leg, init
Parent Code
S88.029
Partial traumatic amputation at knee level, unspecified lower leg

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS80-S89Injuries to the knee and lower leg
CategoryS88Traumatic amputation of lower leg
This CodeS88.029APartial traumatic amputation at knee level, unspecified lower leg, initial encounter

Code EditsBilling

Medicare Code Editor checks that affect claim validity for S88.029A.

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.

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Traumatic amputation of lower leg (S88). 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 INJ014
Amputation of a limb, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Limb Loss

People can lose all or part of an arm or leg for many reasons. Common ones include:

Read the full article at MedlinePlus

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

Convert S88.029A to ICD-9-CMHistory

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

ICD-9-CM
897.2 Amput above knee, unilat
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 S88.029AOverview

Is S88.029A a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report partial traumatic amputation at knee level, unspecified lower leg, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in S88.029A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for partial traumatic amputation at knee level, unspecified lower leg, such as an emergency visit or first evaluation.

What MS-DRG does S88.029A group to?

When partial traumatic amputation at knee level, unspecified lower leg, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 913, 914, 963, 964, 965, with relative weights from 0.8855 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of S88.029A?

Under the General Equivalence Mappings, partial traumatic amputation at knee level, unspecified lower leg, initial encounter converts to ICD-9-CM 897.2 (amput above knee, unilat). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.