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ICD-10-CM 2027 diagnosis code

T30.4Corrosion of unspecified body region, unspecified degree

✓ Billable / specific

T30.4 is a valid, billable ICD-10-CM code for corrosion of unspecified body region, unspecified degree. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Looking up by condition? See ICD-10 code for Corrosion.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About T30.4

T30.4 is the ICD-10-CM diagnosis code for corrosion of unspecified body region, unspecified degree. It belongs to category T30 (burn and corrosion, body region unspecified), block T30-T32 (burns and corrosions of multiple and unspecified body regions) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within T30, choose T30.4 (Corrosion of unspecified body region, unspecified degree) only when documentation doesn't support a more specific option: burn of unspecified body region, unspecified degree (T30.0).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 935 (Non-Extensive Burns, relative weight 2.4243), in MDC 22 (Burns), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 949.0 (burn of unspecified site, unspecified degree).

Coding notes

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

Notes that apply from higher levels

Instructions written at a parent level also apply to T30.4.

Broader instructions also apply from Chapter 19: Injury, poisoning and certain other consequences of external causes.

Alphabetic index entries

1 entries

Terms in the official ICD-10-CM index that lead to T30.4.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

ICD-9-CM equivalent

Converter →
  • 949.0Burn of unspecified site, unspecified degreeapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about T30.4

Is T30.4 billable?

Yes. T30.4 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can T30.4 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict T30.4 as a principal diagnosis.

Is T30.4 a CC or MCC?

No. T30.4 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does T30.4 group to?

T30.4 is used in the MS-DRG v44.0 logic for MS-DRG 935 (Non-Extensive Burns). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for T30.4?

The CMS General Equivalence Mappings map T30.4 to ICD-9-CM 949.0.