T21.42XD — Corrosion of unspecified degree of abdominal wall, subsequent encounter

BillableUnspecified

Is T21.42XD billable?

Yes, but T21.42XD is an unspecified code. T21.42XD is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, T21.42XD is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting T21.42XD — the more specific alternatives are listed below.

More specific alternatives

T21.42XD at a glance

Code	T21.42XD
Description	Corrosion of unspecified degree of abdominal wall, subsequent encounter
Billable	Yes
Code set	ICD-10-CM FY2027
Valid for encounters	October 1, 2026 – September 30, 2027
7th character "D"	subsequent encounter

What does the 7th character "D" mean in T21.42XD?

In T21.42XD, the 7th character D means subsequent encounter. The 7th character is required for T21.42XD to be a valid, complete code.

Same condition, different episode of care — switch the 7th character:

Which MS-DRGs does T21.42XD group to?

T21.42XD sits in MDC 23 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.

949Aftercare with CC/MCCmedical
950Aftercare without CC/MCCmedical

How is T21.42XD listed in the Alphabetic Index?

The Alphabetic Index lists these routes under T21.42, the nearest indexed parent of T21.42XD. Use them to find the family, then select the specific code.

Corrosion › abdomen, abdominal (injury) (acid) (caustic) (chemical) (lime) (external) (internal)

Inclusion terms

Alternative wording in documentation that is classified to T21.42XD.

Corrosion of unspecified degree of flank
Corrosion of unspecified degree of groin

Code first — inherited from T21.4

The underlying condition below must be sequenced before T21.42XD. T21.42XD describes a manifestation and cannot be the principal or first-listed diagnosis.

(T51-T65) to identify chemical and intent

Use additional code — inherited from Chapter 19

Report an additional code alongside T21.42XD to fully describe the condition. T21.42XD is sequenced first.

code to identify any retained foreign body, if applicable (Z18.-)

Use additional code — inherited from T20-T25

Report an additional code alongside T21.42XD to fully describe the condition. T21.42XD is sequenced first.

code from category T31 or T32 to identify extent of body surface involved

Use additional code — inherited from T21.4

Report an additional code alongside T21.42XD to fully describe the condition. T21.42XD is sequenced first.

external cause code to identify place (Y92)

Excludes2 — not included here — inherited from Chapter 19

The conditions below are not part of T21.42XD, but a patient may have both at the same time. When documentation supports it, T21.42XD and the excluded code may both be reported.

birth trauma (P10-P15)
obstetric trauma (O70-O71)

Excludes2 — not included here — inherited from T21

The conditions below are not part of T21.42XD, but a patient may have both at the same time. When documentation supports it, T21.42XD and the excluded code may both be reported.

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)

How long has T21.42XD existed?

T21.42XD has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.

Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.