T21.42XS ICD-10-CM Code: Corrosion of unspecified degree of abdominal wall, sequela
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 (FY2026), Appendix B.
- MS-DRG 604 — TRAUMA TO THE SKIN, SUBCUTANEOUS TISSUE AND BREAST WITH MCC (MDC 09)
- MS-DRG 605 — TRAUMA TO THE SKIN, SUBCUTANEOUS TISSUE AND BREAST WITHOUT MCC (MDC 09)
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.
Code Set: Valid FY2026 and FY2027. FY2026 took effect October 1, 2025.
Official Registry Overview & Definition
Official Tabular Instructional Notes
Sequencing, inclusion, and exclusion notes published for T21.42XS 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]
Inclusion Terms
Alternative terms the tabular list files under this code.
- Corrosion of unspecified degree of flank
- Corrosion of unspecified degree of groin
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)
- burns and corrosion of scapular region (T22.- with fifth character 6)
- burns and corrosion of shoulder (T22.- with fifth character 5)
Code First
Underlying conditions that must be sequenced before this code.
- (T51-T65) to identify chemical and intent
Use Additional Code
Supplementary codes the tabular list directs you to add.
- external cause code to identify place (Y92)
- Use additional code from category T31 or T32 to identify extent of body surface involved
Frequently Asked Questions (FAQ) & Clinical Guidance
Does T21.42XS 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 T21.42XS in its code family, with their registry titles.
- T21.41XD — Corrosion of unspecified degree of chest wall, subsequent encounter
- T21.41XS — Corrosion of unspecified degree of chest wall, sequela
- T21.42 — Corrosion of unspecified degree of abdominal wall
- T21.42XA — Corrosion of unspecified degree of abdominal wall, initial encounter
- T21.42XD — Corrosion of unspecified degree of abdominal wall, subsequent encounter
- T21.43 — Corrosion of unspecified degree of upper back
- T21.43XA — Corrosion of unspecified degree of upper back, initial encounter
- T21.43XD — Corrosion of unspecified degree of upper back, subsequent encounter
- T21.43XS — Corrosion of unspecified degree of upper back, sequela
- T21.44 — Corrosion of unspecified degree of lower back