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T21.34XA ICD-10-CM Code: Burn of third degree of lower back, 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 927 — EXTENSIVE BURNS OR FULL THICKNESS BURNS WITH MV >96 HOURS WITH SKIN GRAFT (MDC 22)
  • MS-DRG 928 — FULL THICKNESS BURN WITH SKIN GRAFT OR INHALATION INJURY WITH CC/MCC (MDC 22)
  • MS-DRG 929 — FULL THICKNESS BURN WITH SKIN GRAFT OR INHALATION INJURY WITHOUT CC/MCC (MDC 22)

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

Burn of third degree of lower back, initial encounter is a billable ICD-10-CM diagnosis code (T21.34A).

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for T21.34XA in the official ICD-10-CM tabular list.

Includes

Conditions the official ICD-10-CM tabular list includes under this code.

  • burns and corrosion of hip region
  • burns and corrosions of first degree [erythema]
  • burns and corrosions of second degree [blisters][epidermal loss]
  • burns and corrosions of third degree [deep necrosis of underlying tissue] [full- thickness skin loss]

Excludes2 — Not Included Here

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

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • external cause code to identify the source, place and intent of the burn (X00-X19, X75-X77, X96-X98, Y92)
  • Use additional code from category T31 or T32 to identify extent of body surface involved

Frequently Compared Codes

The official Excludes notes on T21.34XA 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

Other codes that name T21.34XA 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.

2 Excludes2 notes: T22 (via T21.-), T24 (via T21.-).

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 10 clinically related codes on its CMS exclusion list. Does not count toward severity when the stay groups to DRGs 928-929 (Full Thickness Burn with Skin Graft or Inhalation Injury).

Named in the grouper logic of 3 MS-DRGs: DRG 927 (MDC 22), DRG 928 (MDC 22), DRG 929 (MDC 22).

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

Clinical classification (AHRQ CCSR):INJ019 — Burn and corrosion, 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.

T21.30XA — Burn of third degree of trunk, unspecified site, initial encounter, T21.33XA — Burn of third degree of upper back, initial encounter, T21.35XA — Burn of third degree of buttock, initial encounter, T21.39XA — Burn of third degree of other site of trunk, initial encounter, T21.70XA — Corrosion of third degree of trunk, unspecified site, initial encounter, T21.73XA — Corrosion of third degree of upper back, initial encounter, T21.74XA — Corrosion of third degree of lower back, initial encounter, T21.75XA — Corrosion of third degree of buttock, initial encounter, T21.79XA — Corrosion of third degree of other site of trunk, initial encounter

Same injury, other encounter phase

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

T21.34XD — Burn of third degree of lower back, subsequent encounter Compare T21.34XA vs T21.34XD →, T21.34XS — Burn of third degree of lower back, sequela Compare T21.34XA vs T21.34XS →

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Burn and corrosion, initial encounter).

+935 more

Contextual Map

Every relationship of T21.34XA 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]
  • T20-T25 — Burns and corrosions of external body surface, specified by site [Hierarchy]

Referenced by Excludes2 notes

  • T22 — Burn and corrosion of shoulder and upper limb, except wrist and hand [Excludes2](via T21.-): “burn and corrosion of interscapular region (T21.-)” · check together
  • T24 — Burn and corrosion of lower limb, except ankle and foot [Excludes2](via T21.-): “burn and corrosion of hip region (T21.-)” · check together

Clinical classification (CCSR)

  • INJ019 — Burn and corrosion, 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). Not counted when the stay groups to DRGs 928-929 (Full Thickness Burn with Skin Graft or Inhalation Injury).”
  • DRG 927 — EXTENSIVE BURNS OR FULL THICKNESS BURNS WITH MV >96 HOURS WITH SKIN GRAFT [MS-DRG]: “EXTENSIVE BURNS OR FULL THICKNESS BURNS WITH MV >96 HOURS WITH SKIN GRAFT (MDC 22)”
  • DRG 928 — FULL THICKNESS BURN WITH SKIN GRAFT OR INHALATION INJURY WITH CC/MCC [MS-DRG]: “FULL THICKNESS BURN WITH SKIN GRAFT OR INHALATION INJURY WITH CC/MCC (MDC 22)”
  • DRG 929 — FULL THICKNESS BURN WITH SKIN GRAFT OR INHALATION INJURY WITHOUT CC/MCC [MS-DRG]: “FULL THICKNESS BURN WITH SKIN GRAFT OR INHALATION INJURY WITHOUT CC/MCC (MDC 22)”

MDC crossing · procedures (377)

  • MDC 22 — Burns [MDC crossing]: “Burns — 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.”
  • 0HR0X72 — Replacement of Scalp Skin with Autologous Tissue Substitute, Cell Suspension Technique, External Approach [Same-MDC procedure]: “Replacement of Scalp Skin with Autologous Tissue Substitute, Cell Suspension Technique, External Approach — grouped in MDC 22, the procedure side of this code's crossing.” · check together
  • 0HR0X73 — Replacement of Scalp Skin with Autologous Tissue Substitute, Full Thickness, External Approach [Same-MDC procedure]: “Replacement of Scalp Skin with Autologous Tissue Substitute, Full Thickness, External Approach — grouped in MDC 22, the procedure side of this code's crossing.” · check together
  • 0HR0X74 — Replacement of Scalp Skin with Autologous Tissue Substitute, Partial Thickness, External Approach [Same-MDC procedure]: “Replacement of Scalp Skin with Autologous Tissue Substitute, Partial Thickness, External Approach — grouped in MDC 22, the procedure side of this code's crossing.” · check together
  • 0HR0XJ3 — Replacement of Scalp Skin with Synthetic Substitute, Full Thickness, External Approach [Same-MDC procedure]: “Replacement of Scalp Skin with Synthetic Substitute, Full Thickness, External Approach — grouped in MDC 22, the procedure side of this code's crossing.” · check together
  • 0HR0XJ4 — Replacement of Scalp Skin with Synthetic Substitute, Partial Thickness, External Approach [Same-MDC procedure]: “Replacement of Scalp Skin with Synthetic Substitute, Partial Thickness, External Approach — grouped in MDC 22, the procedure side of this code's crossing.” · check together
  • and 372 more

Nearest codes (40)

  • T21 — Burn and corrosion of trunk [Sibling]
  • T21.29XD — Burn of second degree of other site of trunk, subsequent encounter [Sibling]
  • T21.29XS — Burn of second degree of other site of trunk, sequela [Sibling]
  • T21.3 — Burn of third degree of trunk [Sibling]
  • T21.30 — Burn of third degree of trunk, unspecified site [Sibling]
  • T21.30XA — Burn of third degree of trunk, unspecified site, initial encounter [Sibling]
  • T21.30XD — Burn of third degree of trunk, unspecified site, subsequent encounter [Sibling]
  • T21.30XS — Burn of third degree of trunk, unspecified site, sequela [Sibling]
  • and 32 more

Frequently Asked Questions (FAQ) & Clinical Guidance

Does T21.34XA require a 7th character?

Yes. The appropriate 7th character is to be added to each code from category T21.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to T21.34XA in its code family, with their registry titles.

  • T21.33 — Burn of third degree of upper back
  • T21.33XA — Burn of third degree of upper back, initial encounter
  • T21.33XD — Burn of third degree of upper back, subsequent encounter
  • T21.33XS — Burn of third degree of upper back, sequela
  • T21.34 — Burn of third degree of lower back
  • T21.34XD — Burn of third degree of lower back, subsequent encounter
  • T21.34XS — Burn of third degree of lower back, sequela
  • T21.35 — Burn of third degree of buttock
  • T21.35XA — Burn of third degree of buttock, initial encounter
  • T21.35XD — Burn of third degree of buttock, subsequent encounter

View all codes in the T21 family