T21.50 ICD-10-CM Code: Corrosion of first degree of trunk, unspecified site
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 T21.50 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.
- burns and corrosion of axilla (T22.- with fifth character 4) Compare T21.50 vs T22 →
- burns and corrosion of scapular region (T22.- with fifth character 6) Compare T21.50 vs T22 →
- burns and corrosion of shoulder (T22.- with fifth character 5) Compare T21.50 vs T22 →
Code First
Underlying conditions that must be sequenced before this code.
Indexed Clinical Terms (1)
Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code.
- Corrosion (injury) (acid) (caustic) (chemical) (lime) (external) (internal), trunk, first degree
Frequently Compared Codes
The official Excludes notes on T21.50 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: T21.50XA, T21.50XD, T21.50XS.
- Requires a 7th character. "The appropriate 7th character is to be added to each code from category T21" Options: T21.50XA, T21.50XD, T21.50XS
From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim.
Relationships & Classification
Official ICD-10-CM tabular notes on other codes that name T21.50 or its code family.
Contextual Map
Every relationship of T21.50 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 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
Index entries
- Corrosion (injury) (acid) (caustic) (chemical) (lime) (external) (internal), trunk, first degree[Index term]
Nearest codes (40)
- T21 — Burn and corrosion of trunk [Sibling]
- T21.44XA — Corrosion of unspecified degree of lower back, initial encounter [Sibling]
- T21.44XD — Corrosion of unspecified degree of lower back, subsequent encounter [Sibling]
- T21.44XS — Corrosion of unspecified degree of lower back, sequela [Sibling]
- T21.45 — Corrosion of unspecified degree of buttock [Sibling]
- T21.45XA — Corrosion of unspecified degree of buttock, initial encounter [Sibling]
- T21.45XD — Corrosion of unspecified degree of buttock, subsequent encounter [Sibling]
- T21.45XS — Corrosion of unspecified degree of buttock, sequela [Sibling]
- and 32 more
Frequently Asked Questions (FAQ) & Clinical Guidance
Can T21.50 be billed directly?
No. T21.50 (Corrosion of first degree of trunk, unspecified site) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.
Does T21.50 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 T21.50 in its code family, with their registry titles.
- T21.49 — Corrosion of unspecified degree of other site of trunk
- T21.49XA — Corrosion of unspecified degree of other site of trunk, initial encounter
- T21.49XD — Corrosion of unspecified degree of other site of trunk, subsequent encounter
- T21.49XS — Corrosion of unspecified degree of other site of trunk, sequela
- T21.5 — Corrosion of first degree of trunk
- T21.50XA — Corrosion of first degree of trunk, unspecified site, initial encounter
- T21.50XD — Corrosion of first degree of trunk, unspecified site, subsequent encounter
- T21.50XS — Corrosion of first degree of trunk, unspecified site, sequela
- T21.51 — Corrosion of first degree of chest wall
- T21.51XA — Corrosion of first degree of chest wall, initial encounter