T30.4 Corrosion of unspecified body region, unspecified degree

The ICD-10-CM code for Corrosion of unspecified body region, unspecified degree is T30.4 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

19: Injury, poisoning and certain other consequences of external causes (S00-T88)

Section

T30-T32: Burns and corrosions of multiple and unspecified body regions (T30-T32)

Category T30

3 codes (2 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to T30.4:

• Corrosion (injury) (acid) (caustic) (chemical) (lime) (external) (internal)

Inclusion Terms

• This code is not for inpatient use. Code to specified site and degree of corrosion
• Corrosion NOS
• Multiple corrosion NOS

U.S. Hospital Utilization

T30.4 appeared in too few sampled U.S. inpatient stays in 2023 to report a national estimate (AHRQ suppresses counts of 10 or fewer) — a rare inpatient diagnosis.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

Sequence blood vessel/nerve injury first (fragment)

injury is to the blood vessels or nerves, that injury should be sequenced first.

Do not assign injury codes for iatrogenic injuries; code complication

3) Iatrogenic injuries Injury codes from Chapter 19 should not be assigned for injuries that occur during, or as a result of, a medical intervention. Assign the appropriate complication code(s).

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)