T28.9
Corrosions of other and unspecified internal organs
T28.9 is a non-billable ICD-10-CM code header for corrosions of other and unspecified internal organs. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are T28.90 Corrosions of unspecified internal organs, T28.91 Corrosions of ear drum and T28.99 Corrosions of other internal organs. Its coding notes include a Code first instruction, a Use additional code instruction and 2 Excludes2 entries.
7th characters
Every code below needs one of these (defined at T28).
The appropriate 7th character is to be added to each code from category T28
- Ainitial encounter
- Dsubsequent encounter
- Ssequela
Guidelines tips
From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.
The 7th character depends on whether the patient is in active treatment, not on who sees the patient. An aftercare Z code is not used for injury aftercare.
Late effects of burns are coded with 7th character S, and a current burn and a sequela of an old burn can be coded together. An external cause code is used with burns.
Code first
If the underlying condition listed here is present and known, sequence it first.
- (T51-T65) to identify chemical and intent
Use additional code
Add the listed code as a secondary code, if known.
- external cause code to identify the source and intent of the burn (X00-X19, X75-X77, X96-X98)
- external cause code to identify place (Y92)
Also from chapter/block level (1 note)
- code to identify any retained foreign body, if applicable (Z18.-)
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (2 notes)
- birth trauma (P10-P15)
- obstetric trauma (O70-O71)
Notes
Also from chapter/block level (2 notes)
- Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
- The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.