2026 ICD-10-CM Diagnosis Code S88.121APartial traumatic amputation at level between knee and ankle, right lower leg, initial encounter
ICD-10-CM Codes›S00–T88›S80-S89›S88
- Billable — Valid for Submission
- 7th Character A — Initial Encounter
- Chronic Condition
S88.121A is a billable ICD-10-CM diagnosis code for partial traumatic amputation at level between knee and ankle, right 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. Coders also document this condition as traumatic amputation of right 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.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Traumatic amputation of right lower limb at level between knee and ankle
- Traumatic partial amputation of lower limb at level between knee and ankle
- Traumatic partial amputation of right 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 2026, published by CMS and the National Center for Health Statistics.
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 S88.121A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S88.121AOverview
Is S88.121A a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report partial traumatic amputation at level between knee and ankle, right lower leg, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S88.121A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for partial traumatic amputation at level between knee and ankle, right lower leg, such as an emergency visit or first evaluation.
What MS-DRG does S88.121A group to?
When partial traumatic amputation at level between knee and ankle, right 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 S88.121A?
Under the General Equivalence Mappings, partial traumatic amputation at level between knee and ankle, right lower leg, initial encounter converts to ICD-9-CM 897.0 (amput below 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.
