2027 ICD-10-CM Diagnosis Code S88.022APartial traumatic amputation at knee level, left lower leg, initial encounter
ICD-10-CM Codes›S00–T88›S80-S89›S88
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Risk Adjusts — HCC 405
- 7th Character A — Initial Encounter
- Chronic Condition
S88.022A is a billable ICD-10-CM diagnosis code for partial traumatic amputation at knee level, 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Amputation of a limb, initial encounter.
For Medicare Advantage risk adjustment, S88.022A 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
Code Classification
Medicare Risk Adjustment (HCC)Billing
S88.022A 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.
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.
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 S88.022A: 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.
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.
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- code to identify any retained foreign body, if applicable (Z18.-)
Notes
General instructions on how these codes are used.
- 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.
- 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 S88.022A, its category, or a range that includes it.
Excludes1 4
These codes carry an Excludes1 note naming S88.022A: they are not reported together with it, unless the two conditions are unrelated.
- S78 Traumatic amputation of hip and thightraumatic amputation of knee (S88.0-) names S88.0-, which includes this code
- S78.1 Traumatic amputation at level between hip and kneetraumatic amputation of knee (S88.0-) names S88.0-, which includes this code
- S81 Open wound of knee and lower legtraumatic amputation of lower leg (S88.-) names S88.-, which includes this code
- S82 Fracture of lower leg, including ankletraumatic amputation of lower leg (S88.-) names S88.-, which includes this code
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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 S88.022A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S88.022AOverview
Is S88.022A (Partial traumatic amputation at knee level, left lower leg) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report partial traumatic amputation at knee level, left lower leg, initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What does the 7th character A in S88.022A 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, left lower leg, such as an emergency visit or first evaluation.
What MS-DRG does S88.022A group to?
When partial traumatic amputation at knee level, 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 S88.022A a CC or MCC?
CMS lists S88.022A 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 S88.022A be reported with a code from S98?
Not as a rule. The Excludes1 note at S88, which applies to S88.022A, 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 S88.022A?
S88.022A (partial traumatic amputation at knee level, 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 S88.022A risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, S88.022A 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.
