Alphabetic Index FY2027

T41.42XS

Poisoning by unspecified anesthetic, intentional self-harm, sequela

FY2027Chapter 19: Injury, poisoning and certain other consequences of external causes/T36–T50 Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances

BillableComplete code, valid to report
Care settingsHome Health Primary · MMTA - Other

T41.42XS (also written T4142XS) is a billable ICD-10-CM diagnosis code for poisoning by unspecified anesthetic, intentional self-harm, sequela. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 126 codes in category T41 (Poisoning by, adverse effect of and underdosing of anesthetics and therapeutic gases). Its 7th character, S, means sequela. Its coding notes include a Code first instruction, a Use additional code instruction, 7 Excludes1 entries and 7 Excludes2 entries.

7th character

Category T41 requires a 7th character. T41.42 has only 5 characters, so a placeholder X fills the 6th position.

Assembled code T41.42XS Open code

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.

Guidelines I.C.19.aInjuries: application of 7th charactersRead the official text

T36-T65 codes already include the substance and the intent, so no additional external cause code is required. Do not code directly from the Table of Drugs and Chemicals.

Guidelines I.C.19.ePoisoning, adverse effects and the Table of DrugsRead the official text

Code first

If the underlying condition listed here is present and known, sequence it first.

Also from chapter/block level (7 notes)
Inherited from T36–T50 Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances
  • , for adverse effects, the nature of the adverse effect, such as:
    • adverse effect NOS (T88.7)
    • aspirin gastritis (K29.-)
    • blood disorders (D56-D76)
    • contact dermatitis (L23-L25)
    • dermatitis due to substances taken internally (L27.-)
    • nephropathy (N14.0-N14.2)

Use additional code

Add the listed code as a secondary code, if known.

Also from chapter/block level (5 notes)
Inherited from T36–T50 Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances
  • code(s) to specify:
    • manifestations of poisoning
    • underdosing or failure in dosage during medical and surgical care (Y63.6, Y63.8-Y63.9)
    • underdosing of medication regimen (Z91.12-, Z91.13-)
Inherited from Chapter 19 Injury, poisoning and certain other consequences of external causes
  • code to identify any retained foreign body, if applicable (Z18.-)

Excludes1

Not coded here. The listed conditions generally should not be reported together.

Inherited from T41 Poisoning by, adverse effect of and underdosing of anesthetics and therapeutic gases
  • benzodiazepines (T42.4-)
  • cocaine (T40.5-)
  • complications of anesthesia during pregnancy (O29.-)
  • complications of anesthesia during labor and delivery (O74.-)
  • complications of anesthesia during the puerperium (O89.-)
  • opioids (T40.0-T40.2-)
Also from chapter/block level (1 note)
Inherited from T36–T50 Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances
  • toxic reaction to local anesthesia in pregnancy (O29.3-)

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

Also from chapter/block level (7 notes)
Inherited from T36–T50 Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances
  • abuse and dependence of psychoactive substances (F10-F19)
  • abuse of non-dependence-producing substances (F55.-)
  • immunodeficiency due to drugs (D84.821)
  • drug reaction and poisoning affecting newborn (P00-P96)
  • pathological drug intoxication (inebriation) (F10-F19)
Inherited from Chapter 19 Injury, poisoning and certain other consequences of external causes
  • birth trauma (P10-P15)
  • obstetric trauma (O70-O71)

Care settings

How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.

Home Health Primary

Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the MMTA - Other clinical group.

Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026

Includes

Further defines or gives examples of the content of the category.

Also from chapter/block level (4 notes)
Inherited from T36–T50 Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances
  • adverse effect of correct substance properly administered
  • poisoning by overdose of substance
  • poisoning by wrong substance given or taken in error
  • underdosing by (inadvertently) (deliberately) taking less substance than prescribed or instructed

Notes

Also from chapter/block level (3 notes)
Inherited from T36–T50 Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances
  • The drug giving rise to the adverse effect should be identified by use of codes from categories T36-T50 with fifth or sixth character 5.
Inherited from Chapter 19 Injury, poisoning and certain other consequences of external causes
  • 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.