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S90.55 ICD-10-CM Code: Superficial foreign body of ankle

Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.

Coding at a Glance

7th character
Required — see the character table on this page
Tabular directives
1 inclusion term · 4 Excludes2

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for S90.55 in the official ICD-10-CM tabular list, quoted as published.

Notes without a marker are published on S90.55 itself; “inherited from” names the category or block whose note applies here.

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Splinter in the ankle

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

Source: inherited from S90-S99

7th Character Guide

"The appropriate 7th character is to be added to each code from category S90"

  • A — initial encounter
  • D — subsequent encounter
  • S — sequela

How the encounter character is assigned. “Initial encounter” means the patient is receiving active treatment for the condition — it is not limited to the first visit, and a different or new provider giving active treatment still assigns it. “Subsequent encounter” covers care during the healing or recovery phase after active treatment. “Sequela” is for complications or conditions that arise as a direct result of the original condition.

ICD-10-CM Official Guidelines for Coding and Reporting, Section I.C.19.a (paraphrased by MedCoder).

Variant codes in this family

S90.551A, S90.551D, S90.551S, S90.552A, S90.552D, S90.552S, S90.559A, S90.559D

Character meanings are CMS's official 7th-character extensions for this family, as carried in each variant code's official description; variant codes are registry rows. The explanation of how the encounter character is assigned is MedCoder editorial, distinct from the official content above it.

Code Overview

Superficial foreign body of ankle is a non-billable ICD-10-CM category code (S90.55). A more specific billable subcode must be selected for claims submission.

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Verify Before Coding

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

Other codes that name S90.55 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 11 Excludes2 notes: S80 — Superficial injury of knee and lower leg (via S90.-), S80-S89 — Injuries to the knee and lower leg (S80-S89) (via S90.-), S81 — Open wound of knee and lower leg (via S90.-), S82 — Fracture of lower leg, including ankle (via S90.-), S83 — Dislocation and sprain of joints and ligaments of knee (via S90.-), S84 — Injury of nerves at lower leg level (via S90.-), S85 — Injury of blood vessels at lower leg level (via S90.-), S86 — Injury of muscle, fascia and tendon at lower leg level (via S90.-), S87 — Crushing injury of lower leg (via S90.-), S88 — Traumatic amputation of lower leg (via S90.-), S89 — Other and unspecified injuries of lower leg (via S90.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

Related Codes

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Foreign body”; these codes share that main term but sit in a different category of the Tabular List.

S50.85 — Superficial foreign body of forearm (superficial, without open wound, forearm), S60.35 — Superficial foreign body of thumb (superficial, without open wound, thumb), S60.45 — Superficial foreign body of fingers (superficial, without open wound, finger, ring), S60.459 — Superficial foreign body of unspecified finger (superficial, without open wound, finger), S60.55 — Superficial foreign body of hand (superficial, without open wound, hand), S60.85 — Superficial foreign body of wrist (superficial, without open wound, wrist), S70.25 — Superficial foreign body of hip (superficial, without open wound, hip), S70.35 — Superficial foreign body of thigh (superficial, without open wound, thigh), S80.25 — Superficial foreign body of knee (superficial, without open wound, knee), S80.85 — Superficial foreign body of lower leg (superficial, without open wound, leg), T15.0 — Foreign body in cornea (cornea), T15.1 — Foreign body in conjunctival sac (conjunctival sac), T15.8 — Foreign body in other and multiple parts of external eye (entering through orifice, eye NOS, specified part NEC), T15.9 — Foreign body on external eye, part unspecified (entering through orifice, eye NOS), T17.0 — Foreign body in nasal sinus (respiratory tract, nasal sinus), T17.1 — Foreign body in nostril (respiratory tract, nose), T17.200 — Unspecified foreign body in pharynx causing asphyxiation (pharynx, causing, asphyxiation), T17.208 — Unspecified foreign body in pharynx causing other injury (pharynx), T17.210 — Gastric contents in pharynx causing asphyxiation (pharynx, causing, asphyxiation, gastric contents), T17.218 — Gastric contents in pharynx causing other injury (pharynx, causing, injury NEC, gastric contents), +176 more

Contextual Map

Every relationship of S90.55 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run S90.55 with these 8 related codes in Claim Check

Hierarchy

Referenced by Excludes2 notes (11)

Nearest codes (40)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Common coding questions

Can S90.55 be billed directly?

No. S90.55 (Superficial foreign body of ankle) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.

Does S90.55 require a 7th character?

Yes. The appropriate 7th character is to be added to each code from category S90.

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Superficial foreign body of ankle

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to S90.55 in its code family, with their registry titles.

View all codes in the S90 family