T33.81 ICD-10-CM Code: Superficial frostbite of ankle
Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.
Official Registry Overview & Definition
Official Tabular Instructional Notes
Sequencing, inclusion, and exclusion notes published for T33.81 in the official ICD-10-CM tabular list.
Includes
Conditions the official ICD-10-CM tabular list includes under this code.
- frostbite with partial thickness skin loss
Excludes2 — Not Included Here
Conditions not covered by this code, but which may be reported alongside it when both are present.
- hypothermia and other effects of reduced temperature (T68, T69.-) Compare T33.81 vs T68 →
Frequently Compared Codes
The official Excludes notes on T33.81 name these codes. Each comparison page covers when the two can — or must not — be reported together.
Change history
No changes recorded for this code — unchanged since the FY2016 baseline of the change ledger.
Verify Before Coding
- Not billable as written — a more specific code is required.
- Requires a 7th character. "The appropriate 7th character is to be added to each code from category T33" Options: T33.811A, T33.811D, T33.811S, T33.812A, T33.812D, T33.812S
From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim.
Relationships & Classification
Other codes that name T33.81 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.
1 Excludes1 notes: T07 (via T33.-).
113 Excludes2 notes across 2 chapters: I73 (via T33.-), S00 (via T33.-), S00-S09 (via T33.-), S01 (via T33.-), S02 (via T33.-), S03 (via T33.-), S04 (via T33.-), S05 (via T33.-), S06 (via T33.-), S07 (via T33.-), S08 (via T33.-), S09 (via T33.-), S10 (via T33.-), S10-S19 (via T33.-), S11 (via T33.-), S12 (via T33.-), S13 (via T33.-), S14 (via T33.-), S15 (via T33.-), S16 (via T33.-), +93 more.
Contextual Map
Every relationship of T33.81 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.
Hierarchy
- S00-T88 — Chapter 19: Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) (S00-T88) [Hierarchy]
Referenced by Excludes1 notes
- T07 — Unspecified multiple injuries [Excludes1](via T33.-): “frostbite (T33-T34)” · check together
Referenced by Excludes2 notes (113)
- I73 — Other peripheral vascular diseases [Excludes2](via T33.-): “frostbite (T33-T34)” · check together
- S00 — Superficial injury of head [Excludes2](via T33.-): “frostbite (T33-T34)” · check together
- S00-S09 — Injuries to the head (S00-S09) [Excludes2](via T33.-): “frostbite (T33-T34)” · check together
- S01 — Open wound of head [Excludes2](via T33.-): “frostbite (T33-T34)” · check together
- S02 — Fracture of skull and facial bones [Excludes2](via T33.-): “frostbite (T33-T34)” · check together
- S03 — Dislocation and sprain of joints and ligaments of head [Excludes2](via T33.-): “frostbite (T33-T34)” · check together
- S04 — Injury of cranial nerve [Excludes2](via T33.-): “frostbite (T33-T34)” · check together
- S05 — Injury of eye and orbit [Excludes2](via T33.-): “frostbite (T33-T34)” · check together
- and 105 more
Nearest codes (40)
- T33 — Superficial frostbite [Sibling]
- T33.61XD — Superficial frostbite of right hip and thigh, subsequent encounter [Sibling]
- T33.61XS — Superficial frostbite of right hip and thigh, sequela [Sibling]
- T33.62 — Superficial frostbite of left hip and thigh [Sibling]
- T33.62XA — Superficial frostbite of left hip and thigh, initial encounter [Sibling]
- T33.62XD — Superficial frostbite of left hip and thigh, subsequent encounter [Sibling]
- T33.62XS — Superficial frostbite of left hip and thigh, sequela [Sibling]
- T33.7 — Superficial frostbite of knee and lower leg [Sibling]
- and 32 more
Frequently Asked Questions (FAQ) & Clinical Guidance
Can T33.81 be billed directly?
No. T33.81 (Superficial frostbite of ankle) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.
Does T33.81 require a 7th character?
Yes. The appropriate 7th character is to be added to each code from category T33.
Nearest Codes in This Family
Official ICD-10-CM classifications closest to T33.81 in its code family, with their registry titles.
- T33.72 — Superficial frostbite of left knee and lower leg
- T33.72XA — Superficial frostbite of left knee and lower leg, initial encounter
- T33.72XD — Superficial frostbite of left knee and lower leg, subsequent encounter
- T33.72XS — Superficial frostbite of left knee and lower leg, sequela
- T33.8 — Superficial frostbite of ankle, foot, and toe(s)
- T33.811 — Superficial frostbite of right ankle
- T33.811A — Superficial frostbite of right ankle, initial encounter
- T33.811D — Superficial frostbite of right ankle, subsequent encounter
- T33.811S — Superficial frostbite of right ankle, sequela
- T33.812 — Superficial frostbite of left ankle