Skip to main content

T34.99XA ICD-10-CM Code: Frostbite with tissue necrosis of other sites, initial encounter

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Inpatient Payment Groups (MS-DRG)

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43.0, Appendix B.

  • MS-DRG 922 — OTHER INJURY, POISONING AND TOXIC EFFECT DIAGNOSES WITH MCC (MDC 21)
  • MS-DRG 923 — OTHER INJURY, POISONING AND TOXIC EFFECT DIAGNOSES WITHOUT MCC (MDC 21)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Official Registry Overview & Definition

Frostbite with tissue necrosis of other sites, initial encounter is a billable ICD-10-CM diagnosis code (T34.99A).

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for T34.99XA in the official ICD-10-CM tabular list.

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Frostbite with tissue necrosis of leg NOS
  • Frostbite with tissue necrosis of trunk NOS

Excludes2 — Not Included Here

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

Frequently Compared Codes

The official Excludes notes on T34.99XA 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

  • CC as a secondary diagnosis (FY2026). Can raise the stay's MS-DRG severity tier.

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

Relationships & Classification

Potential MS-DRG Relationships (FY2026)

CC — Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 77 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 2 MS-DRGs: DRG 922 (MDC 21), DRG 923 (MDC 21).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):INJ021 — Effect of other external causes, initial encounter (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical process (MS-DRG)

Acts as CC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

T34.539A — Frostbite with tissue necrosis of unspecified finger(s), initial encounter, T34.60XA — Frostbite with tissue necrosis of unspecified hip and thigh, initial encounter, T34.61XA — Frostbite with tissue necrosis of right hip and thigh, initial encounter, T34.62XA — Frostbite with tissue necrosis of left hip and thigh, initial encounter, T34.70XA — Frostbite with tissue necrosis of unspecified knee and lower leg, initial encounter, T34.71XA — Frostbite with tissue necrosis of right knee and lower leg, initial encounter, T34.72XA — Frostbite with tissue necrosis of left knee and lower leg, initial encounter, T34.811A — Frostbite with tissue necrosis of right ankle, initial encounter, T34.812A — Frostbite with tissue necrosis of left ankle, initial encounter, T34.819A — Frostbite with tissue necrosis of unspecified ankle, initial encounter, T34.821A — Frostbite with tissue necrosis of right foot, initial encounter, T34.822A — Frostbite with tissue necrosis of left foot, initial encounter, T34.829A — Frostbite with tissue necrosis of unspecified foot, initial encounter, T34.831A — Frostbite with tissue necrosis of right toe(s), initial encounter, T34.832A — Frostbite with tissue necrosis of left toe(s), initial encounter, T34.839A — Frostbite with tissue necrosis of unspecified toe(s), initial encounter, T34.90XA — Frostbite with tissue necrosis of unspecified sites, initial encounter, T69.021A — Immersion foot, right foot, initial encounter, T69.022A — Immersion foot, left foot, initial encounter, T69.029A — Immersion foot, unspecified foot, initial encounter, +56 more

Same injury, other encounter phase

Same injury, coded at a different phase of treatment via the 7th character.

T34.99XD — Frostbite with tissue necrosis of other sites, subsequent encounter Compare T34.99XA vs T34.99XD →, T34.99XS — Frostbite with tissue necrosis of other sites, sequela Compare T34.99XA vs T34.99XS →

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Effect of other external causes, initial encounter).

T34.811A — Frostbite with tissue necrosis of right ankle, initial encounter, T34.812A — Frostbite with tissue necrosis of left ankle, initial encounter, T34.819A — Frostbite with tissue necrosis of unspecified ankle, initial encounter, T34.821A — Frostbite with tissue necrosis of right foot, initial encounter, T34.822A — Frostbite with tissue necrosis of left foot, initial encounter, T34.829A — Frostbite with tissue necrosis of unspecified foot, initial encounter, T34.831A — Frostbite with tissue necrosis of right toe(s), initial encounter, T34.832A — Frostbite with tissue necrosis of left toe(s), initial encounter, T34.839A — Frostbite with tissue necrosis of unspecified toe(s), initial encounter, T34.90XA — Frostbite with tissue necrosis of unspecified sites, initial encounter, T66.XXXA — Radiation sickness, unspecified, initial encounter, T67.01XA — Heatstroke and sunstroke, initial encounter, T67.02XA — Exertional heatstroke, initial encounter, T67.09XA — Other heatstroke and sunstroke, initial encounter, T67.1XXA — Heat syncope, initial encounter, T67.2XXA — Heat cramp, initial encounter, T67.3XXA — Heat exhaustion, anhydrotic, initial encounter, T67.4XXA — Heat exhaustion due to salt depletion, initial encounter, T67.5XXA — Heat exhaustion, unspecified, initial encounter, T67.6XXA — Heat fatigue, transient, initial encounter, +149 more

Contextual Map

Every relationship of T34.99XA 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]
  • T33-T34 — Frostbite [Hierarchy]

Clinical classification (CCSR)

  • INJ021 — Effect of other external causes, initial encounter [CCSR]

Potential MS-DRG

  • CC — Complication or Comorbidity [MS-DRG severity]: “As a secondary diagnosis this code can raise the stay's MS-DRG severity tier (CC).”
  • DRG 922 — OTHER INJURY, POISONING AND TOXIC EFFECT DIAGNOSES WITH MCC [MS-DRG]: “OTHER INJURY, POISONING AND TOXIC EFFECT DIAGNOSES WITH MCC (MDC 21)”
  • DRG 923 — OTHER INJURY, POISONING AND TOXIC EFFECT DIAGNOSES WITHOUT MCC [MS-DRG]: “OTHER INJURY, POISONING AND TOXIC EFFECT DIAGNOSES WITHOUT MCC (MDC 21)”

MDC crossing · procedures (32029)

  • MDC 21 — Injuries, Poisonings and Toxic Effects of Drugs [MDC crossing]: “Injuries, Poisonings and Toxic Effects of Drugs — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs.”
  • 0016070 — Bypass Cerebral Ventricle to Nasopharynx with Autologous Tissue Substitute, Open Approach [Same-MDC procedure]: “Bypass Cerebral Ventricle to Nasopharynx with Autologous Tissue Substitute, Open Approach — grouped in MDC 21, the procedure side of this code's crossing.” · check together
  • 0016071 — Bypass Cerebral Ventricle to Mastoid Sinus with Autologous Tissue Substitute, Open Approach [Same-MDC procedure]: “Bypass Cerebral Ventricle to Mastoid Sinus with Autologous Tissue Substitute, Open Approach — grouped in MDC 21, the procedure side of this code's crossing.” · check together
  • 0016072 — Bypass Cerebral Ventricle to Atrium with Autologous Tissue Substitute, Open Approach [Same-MDC procedure]: “Bypass Cerebral Ventricle to Atrium with Autologous Tissue Substitute, Open Approach — grouped in MDC 21, the procedure side of this code's crossing.” · check together
  • 0016073 — Bypass Cerebral Ventricle to Blood Vessel with Autologous Tissue Substitute, Open Approach [Same-MDC procedure]: “Bypass Cerebral Ventricle to Blood Vessel with Autologous Tissue Substitute, Open Approach — grouped in MDC 21, the procedure side of this code's crossing.” · check together
  • 0016074 — Bypass Cerebral Ventricle to Pleural Cavity with Autologous Tissue Substitute, Open Approach [Same-MDC procedure]: “Bypass Cerebral Ventricle to Pleural Cavity with Autologous Tissue Substitute, Open Approach — grouped in MDC 21, the procedure side of this code's crossing.” · check together
  • and 32024 more

Nearest codes (40)

  • T34 — Frostbite with tissue necrosis [Sibling]
  • T34.812D — Frostbite with tissue necrosis of left ankle, subsequent encounter [Sibling]
  • T34.812S — Frostbite with tissue necrosis of left ankle, sequela [Sibling]
  • T34.819 — Frostbite with tissue necrosis of unspecified ankle [Sibling]
  • T34.819A — Frostbite with tissue necrosis of unspecified ankle, initial encounter [Sibling]
  • T34.819D — Frostbite with tissue necrosis of unspecified ankle, subsequent encounter [Sibling]
  • T34.819S — Frostbite with tissue necrosis of unspecified ankle, sequela [Sibling]
  • T34.82 — Frostbite with tissue necrosis of foot [Sibling]
  • and 32 more

Frequently Asked Questions (FAQ) & Clinical Guidance

Does T34.99XA require a 7th character?

Yes. The appropriate 7th character is to be added to each code from category T34.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to T34.99XA in its code family, with their registry titles.

  • T34.839A — Frostbite with tissue necrosis of unspecified toe(s), initial encounter
  • T34.839D — Frostbite with tissue necrosis of unspecified toe(s), subsequent encounter
  • T34.839S — Frostbite with tissue necrosis of unspecified toe(s), sequela
  • T34.9 — Frostbite with tissue necrosis of other and unspecified sites
  • T34.90 — Frostbite with tissue necrosis of unspecified sites
  • T34.90XA — Frostbite with tissue necrosis of unspecified sites, initial encounter
  • T34.90XD — Frostbite with tissue necrosis of unspecified sites, subsequent encounter
  • T34.90XS — Frostbite with tissue necrosis of unspecified sites, sequela
  • T34.99 — Frostbite with tissue necrosis of other sites
  • T34.99XD — Frostbite with tissue necrosis of other sites, subsequent encounter

View all codes in the T34 family