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S91.052 ICD-10-CM Code: Open bite, left 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
3 Excludes1 · 4 Excludes2 · 1 code-also instruction

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for S91.052 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on S91.052 itself; “inherited from” names the category or block whose note applies here.

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

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

Code Also

Additional codes that may be required to fully describe the encounter.

  • any associated wound infection

Source: inherited from S91

7th Character Guide

"The appropriate 7th character is to be added to each code from category S91"

  • 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

S91.052A, S91.052D, S91.052S

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.

Coder workflow for S91.052

MedCoder structured workflow — derived from this code’s own official record

Before you code S91.052

  1. S91.052 is not reportable as written. Select the more specific code beneath it that the documentation supports. Codes are reported to the highest level of specificity the classification provides (Guidelines I.B.2).

    ReviewS91.052A, S91.052D, S91.052S

    See the relationships section · Guide: How to choose an ICD-10-CM code →

  2. A 7th character is required in this family. Confirm the documented encounter: initial (active treatment), subsequent (healing or recovery phase), or sequela. S91.052 is not valid without one. “Initial” means active treatment, not the first visit (Guidelines I.C.19.a).

    See the 7th Character Guide · Guide: 7th characters: initial, subsequent, sequela →

  3. Laterality is coded in this family. Confirm the side documented — right, left, or bilateral — and select the matching code (this page’s code: left). The unspecified-side code applies only when the record states no side. Laterality is assigned from the documented side; where a bilateral code exists and both sides are documented, it is used instead of two unilateral codes (Guidelines I.B.13).

    ReviewS91.051 · right, S91.059 · unspecified

    Guide: Laterality coding →

  4. Confirm the injury type, the anatomical site at the most specific level documented, laterality where the family codes it, and the encounter for the 7th character. Each injury is coded separately unless the classification provides a combination code, and a superficial injury is not coded when a more severe injury of the same site is documented. Injury chapter guidelines (Guidelines I.C.19.b, I.C.19.b.1).

    Guide: 7th characters: initial, subsequent, sequela →

  5. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with S91.052. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Does the documentation support one of the more specific codes beneath S91.052?
    Yes → Select that code and continue the checks below on its own page.
    No → S91.052 cannot be reported as written; query for the specificity its subcategory needs.

    ReviewS91.052A, S91.052D, S91.052S

  2. Does the documentation support a condition named in S91.052’s Excludes1 note?
    Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
    No → Continue.

    ReviewS90.56, S90.57, S92, S98

  3. Is the side documented?
    Yes → Select the code for the documented side (or the bilateral code when both sides are documented and one exists).
    No → Use the unspecified-side code only when the record states no side; a query is the alternative.

    ReviewS91.051 · right, S91.059 · unspecified

  4. Is the encounter phase documented — active treatment, healing or recovery, or a sequela?
    Yes → Assign the matching 7th character; the variant codes are in the 7th Character Guide.
    No → The code is invalid without its 7th character — query for the missing element.

Consider S91.052. Then review the Code Also note, and confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
Anatomical site
At the most specific level the record states; a site the classification separates cannot be assumed from a procedure or a measurement.
Laterality
Right, left or bilateral as documented; unspecified only when the record states no side (Guidelines I.B.13).
Encounter type
Active treatment, healing or recovery phase, or sequela — the basis of the 7th character (Guidelines I.C.19.a).
Open or closed; displaced or nondisplaced
Defaults apply when the record is silent: closed, and displaced (Guidelines I.C.19.c).
External cause, place and activity
For the external cause codes reported with the injury or poisoning, where documented (Guidelines I.C.20.a).

Official instructions as workflow

  • Excludes1 — check before selecting S91.052(3 notes)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with S91.052: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareS90.56, S90.57, S92, S98

    See the official tabular notes · Guidelines I.A.12.a

  • Excludes2 — not part of S91.052(4 notes)

    Coding workflow: The conditions named in this note are not included in S91.052. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareS82, T63.4

    See the official tabular notes · Guidelines I.A.12.b

  • Code Also — related condition(1 note)

    Coding workflow: Review the related condition when both are documented and the instruction applies. A Code Also note does not fix sequencing; the order follows the circumstances of the encounter.

    See the official tabular notes · Guidelines I.A.17

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: Both the condition S91.052 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewS90.56, S90.57, S92, S98

Documentation: The patient returns during the healing or recovery phase after active treatment of the same condition.

Coding question: Which 7th character applies?

Path: Review the official 7th-character definitions for this family in the 7th Character Guide.

Reason: “Initial encounter” means active treatment, not the first visit; care during recovery takes “subsequent encounter”, and a complication arising from the original condition takes “sequela” (Guidelines I.C.19.a).

Documentation: The record documents the condition on one side only.

Coding question: Which code in this family applies?

Path: Select the sibling code for the documented side.

Reason: Laterality is assigned from the documented side; the unspecified-side code is for records that state no side (Guidelines I.B.13).

ReviewS91.051 · right, S91.059 · unspecified

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Code Overview

Open bite, left ankle is a non-billable ICD-10-CM category code (S91.052). 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.

Decision Points

The directives on this code's own record, as a pre-claim checklist.

  1. A 7th character applies in this family. Confirm the documented encounter matches the character assigned. See the official 7th-character definitions and this code’s variants
  2. Laterality is coded in this family. Confirm the documented side matches the code — the opposite-side siblings are in the relationships section. See the opposite-side sibling codes
  3. 1 Code Also note — a second code may apply; the guidelines leave its sequencing to the circumstances of the encounter. See the Code Also notes
  4. 3 Excludes1 entries — codes named there are generally not reported together with this code (Guidelines I.A.12.a). See the Excludes1 notes
  5. 4 Excludes2 entries — those conditions are not part of this code and may be reported additionally when documented. See the Excludes2 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

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

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name S91.052 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 1 Excludes1 note: S90.57 — Other superficial bite of ankle (via S91.05.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 12 Excludes2 notes: S71 — Open wound of hip and thigh (via S91.-), S80 — Superficial injury of knee and lower leg (via S91.-), S80-S89 — Injuries to the knee and lower leg (S80-S89) (via S91.-), S81 — Open wound of knee and lower leg (via S91.-), S82 — Fracture of lower leg, including ankle (via S91.-), S83 — Dislocation and sprain of joints and ligaments of knee (via S91.-), S84 — Injury of nerves at lower leg level (via S91.-), S85 — Injury of blood vessels at lower leg level (via S91.-), S86 — Injury of muscle, fascia and tendon at lower leg level (via S91.-), S87 — Crushing injury of lower leg (via S91.-), S88 — Traumatic amputation of lower leg (via S91.-), S89 — Other and unspecified injuries of lower leg (via S91.-).

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

Referenced by 3 Code Also instructions: S94 — Injury of nerves at ankle and foot level (via S91.-), S95 — Injury of blood vessels at ankle and foot level (via S91.-), S96 — Injury of muscle and tendon at ankle and foot level (via S91.-).

These codes suggest coding this condition alongside when both are present.

Related Codes

Same condition, opposite side

Same category and title, differing only in which side of the body is affected.

S91.051 — Open bite, right ankle (right)Compare S91.052 vs S91.051 →, S91.059 — Open bite, unspecified ankle (unspecified)Compare S91.052 vs S91.059 →

Same Index main term, other category

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

S61.45 — Open bite of hand (hand), S61.55 — Open bite of wrist (wrist), S70.26 — Insect bite (nonvenomous) of hip (hip, superficial NEC, insect), S70.27 — Other superficial bite of hip (hip, superficial NEC), S70.36 — Insect bite (nonvenomous) of thigh (thigh, superficial NEC, insect), S70.37 — Other superficial bite of thigh (thigh, superficial NEC), S71.05 — Open bite of hip (hip), S71.15 — Open bite of thigh (thigh), S80.26 — Insect bite (nonvenomous) of knee (knee, superficial NEC, insect), S80.27 — Other superficial bite of knee (knee, superficial NEC), S80.86 — Insect bite (nonvenomous) of lower leg (leg, superficial NEC, insect), S80.87 — Other superficial bite of lower leg (leg, superficial NEC), S81.05 — Open bite of knee (knee), S81.85 — Open bite of lower leg (leg), S90.46 — Insect bite (nonvenomous) of toe (toe, superficial NEC, insect), S90.47 — Other superficial bite of toe (toe, superficial NEC), S90.56 — Insect bite (nonvenomous) of ankle (ankle, superficial NEC, insect), S90.57 — Other superficial bite of ankle (ankle, superficial NEC), S90.86 — Insect bite (nonvenomous) of foot (foot, superficial NEC, insect), S90.87 — Other superficial bite of foot (foot, superficial NEC), +137 more

Contextual Map

Every relationship of S91.052 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 S91.052 with these 12 related codes in Claim Check

Hierarchy

Referenced by Excludes1 notes

Referenced by Excludes2 notes (12)

Referenced by Code Also instructions

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 S91.052 be billed directly?

No. S91.052 (Open bite, left ankle) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.

Does S91.052 require a 7th character?

Yes. The appropriate 7th character is to be added to each code from category S91.

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

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "S91.052 — Open bite, left ankle." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/s91.052-open-bite-left-ankle

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Open bite, left 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 S91.052 in its code family, with their registry titles.

View all codes in the S91 family