2027 ICD-10-CM Diagnosis Code S88.112AComplete traumatic amputation at level between knee and ankle, left lower leg, initial encounter

ICD-10-CM Codes›S00–T88›S80-S89›S88

ICD-10-CM S88.112A
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

S88.112A is a billable ICD-10-CM diagnosis code for complete traumatic amputation at level between knee and ankle, left 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. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 229 closely related codes. Coders also document this condition as traumatic amputation of left lower limb at level between knee and ankle. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Amputation of a limb, initial encounter.

For Medicare Advantage risk adjustment, S88.112A maps to CMS-HCC Category 405 (Traumatic Amputations and Complications) under the V28 model, adding a risk factor of about 0.598 for a community, non-dual, aged beneficiary in payment year 2027.

Code Identity

ICD-10-CM Code
S88.112A
Billable Status
Yes — Valid for Submission
Code Describes
Complete traumatic amputation at level between knee and ankle, left lower leg, initial encounter
Short Description
Complete traum amp at lev betw kn and ankl, l low leg, init
Parent Code
Complete traumatic amputation at level between knee and ankle, left 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 CodeS88.112AComplete traumatic amputation at level between knee and ankle, left lower leg, initial encounter

Medicare Risk Adjustment (HCC)Billing

S88.112A maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.

CMS-HCC V28 Category (Payment Model)
HCC 405— Traumatic Amputations and Complications
Payment HCC · PY 2027 one of 108 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.598
community, non-dual, aged · ranges 0.284–0.844 across segments
Hierarchy
Supersedes HCC 409
less severe related categories are not paid alongside HCC 405
Prior Model (CMS-HCC V24)
HCC 173
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 173 · ESRD (V21): HCC 173 · ESRD (V24): HCC 173
ESRD V21 weights: 0.042 dialysis, 0.061–0.290 functioning graft · ESRD V24 weights: 0.050 dialysis, 0.000–0.341 functioning graft
Part D (RxHCC)
Not mapped
S88.112A does not risk-adjust in the RxHCC prescription drug model

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Traumatic amputation of left lower limb at level between knee and ankle
  • Traumatic transtibiofibular amputation

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 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 S88.112A: its own notes plus those printed at S88, 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 S88 Traumatic amputation of lower leg applies to 54 codes
  • traumatic amputation of ankle and foot (S98.-)

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 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.-)

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 S88 Traumatic amputation of lower leg applies to 54 codes
  • The appropriate 7th character is to be added to each code from category S88
  • 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 S88.112A, its category, or a range that includes it.

Excludes1 2

These codes carry an Excludes1 note naming S88.112A: they are not reported together with it, unless the two conditions are unrelated.

  • S81 Open wound of knee and lower leg
    traumatic amputation of lower leg (S88.-) names S88.-, which includes this code
  • S82 Fracture of lower leg, including ankle
    traumatic amputation of lower leg (S88.-) names S88.-, which includes this code

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 S88.112A to ICD-9-CMHistory

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

ICD-9-CM
897.0 Amput below 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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About S88.112AOverview

Is S88.112A a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report complete traumatic amputation at level between knee and ankle, left lower leg, initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character A in S88.112A mean?

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

What MS-DRG does S88.112A group to?

When complete traumatic amputation at level between knee and ankle, left 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.

Is S88.112A a CC or MCC?

CMS lists S88.112A as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 229 closely related codes in its exclusion list.

Can S88.112A be reported with a code from S98?

Not as a rule. The Excludes1 note at S88, which applies to S88.112A, lists "traumatic amputation of ankle and foot (S98.-)". 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).

What HCC is S88.112A?

S88.112A (complete traumatic amputation at level between knee and ankle, left lower leg, initial encounter) maps to CMS-HCC Category 405 (Traumatic Amputations and Complications), commonly written as HCC 405, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 173 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. It does not map to any RxHCC in the Part D prescription drug model.

Does S88.112A risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, S88.112A adds a risk adjustment factor of about 0.598 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.284 to 0.844 depending on the payment segment). HCC 405 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 405 category page.