FY2027 ICD-10-CM reference
S88.021S: Partial traumatic amputation at knee level, right lower leg, sequela
By the HCC Buddy Coding Team
The official ICD-10-CM descriptor is Partial traumatic amputation at knee level, right lower leg, sequela. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Billable code. Verified against the official FY2027 order file.
FY2027 Tabular instructions
Instructions below include applicable chapter, section and parent-code notes. Each note identifies where it appears in the official source.
Instructional note
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
Source: S00-T88 (chapter, inherited).
Instructional note
code to identify any retained foreign body, if applicable (Z18.-)
Source: S00-T88 (chapter, inherited).
Excludes2
birth trauma (P10-P15)
Source: S00-T88 (chapter, inherited).
Excludes2
obstetric trauma (O70-O71)
Source: S00-T88 (chapter, inherited).
Instructional note
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.
Source: S00-T88 (chapter, inherited).
Excludes2
burns and corrosions (T20-T32)
Source: S80-S89 (section, inherited).
Excludes2
frostbite (T33-T34)
Source: S80-S89 (section, inherited).
Excludes2
injuries of ankle and foot, except fracture of ankle and malleolus (S90-S99)
Source: S80-S89 (section, inherited).
Excludes2
insect bite or sting, venomous (T63.4)
Source: S80-S89 (section, inherited).
Instructional note
An amputation not identified as partial or complete should be coded to complete
Source: S88 (category, inherited).
Excludes1
traumatic amputation of ankle and foot (S98.-)
Source: S88 (category, inherited).
Seventh-character instruction
The appropriate 7th character is to be added to each code from category S88
Source: S88 (category, inherited).
Instructional note
initial encounter
Source: S88 (category, inherited).
Instructional note
subsequent encounter
Source: S88 (category, inherited).
Instructional note
sequela
Source: S88 (category, inherited).
Seventh-character definitions
- A: initial encounter
- D: subsequent encounter
- S: sequela
Compare the FY2027 additions, removals and billable-status changes
What does S88.021S mean in FY2027?
The official ICD-10-CM descriptor is Partial traumatic amputation at knee level, right lower leg, sequela. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Is S88.021S billable in FY2027?
The FY2027 order file marks S88.021S as billable. Check the complete Tabular instructions and documentation before assigning it.
Does S88.021S map to an HCC?
S88.021S has no CMS-HCC V28 category in the CMS 2027 Initial ICD-10-CM Mappings (payment year 2027, 2026 dates of service). Under the PY2026 CMS mapping; CMS 2027 initial file unchanged: ESRD HCC 189; no RxHCC category. Coefficients for these models are pending verification for payment year 2027. HHS-HCC: no category in the HHS-HCC 2026 benefit year mapping. CMS-HCC V24: not used for payment year 2027 Medicare Advantage payment (CMS CY 2027 Rate Announcement). The PACE mapping is still pending verification for FY2027.
Source: CMS FY2027 ICD-10-CM order file. Payment model: CMS CY 2027 Rate Announcement. Read the FY2027 Official Guidelines.
Review the FY2026 April edition