ICDcodes.org
FY2027

T20.42XSCorrosion of unspecified degree of lip(s), sequela

BillableUnspecified

Is T20.42XS billable?

Yes, but T20.42XS is an unspecified code. T20.42XS is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, T20.42XS 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 T20.42XS — the more specific alternatives are listed below.

T20.42XS at a glance

CodeT20.42XS
DescriptionCorrosion of unspecified degree of lip(s), sequela
BillableYes
Code setICD-10-CM FY2027
Valid for encountersOctober 1, 2026 – September 30, 2027
7th character "S"sequela

What does the 7th character "S" mean in T20.42XS?

In T20.42XS, the 7th character S means sequela. The 7th character is required for T20.42XS to be a valid, complete code.

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

Which MS-DRGs does T20.42XS group to?

T20.42XS sits in MDC 09 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.

  • 604Trauma to the Skin, Subcutaneous Tissue and Breast with MCCmedical
  • 605Trauma to the Skin, Subcutaneous Tissue and Breast without MCCmedical

How is T20.42XS listed in the Alphabetic Index?

The Alphabetic Index lists these routes under T20.42, the nearest indexed parent of T20.42XS. Use them to find the family, then select the specific code.

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

Code first — inherited from T20.4

The underlying condition below must be sequenced before T20.42XS. T20.42XS 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 T20.42XS to fully describe the condition. T20.42XS 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 T20.42XS to fully describe the condition. T20.42XS is sequenced first.

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

Use additional code — inherited from T20.4

Report an additional code alongside T20.42XS to fully describe the condition. T20.42XS 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 T20.42XS, but a patient may have both at the same time. When documentation supports it, T20.42XS and the excluded code may both be reported.

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

Excludes2 — not included here — inherited from T20

The conditions below are not part of T20.42XS, but a patient may have both at the same time. When documentation supports it, T20.42XS and the excluded code may both be reported.

  • burn and corrosion of ear drum (T28.41, T28.91)
  • burn and corrosion of eye and adnexa (T26.-)
  • burn and corrosion of mouth and pharynx (T28.0)

How long has T20.42XS existed?

T20.42XS 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.