2027 ICD-10-CM Diagnosis Code T37Poisoning by, adverse effect of and underdosing of other systemic anti-infectives and antiparasitics

ICD-10-CM Codes›S00–T88›T36-T50›T37

ICD-10-CM T37
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

T37 is a non-billable ICD-10-CM category code for poisoning by, adverse effect of and underdosing of other systemic anti-infectives and antiparasitics, so it cannot be submitted on claims. Use a more specific code from this category instead, such as T37.0X1A, T37.0X1D, T37.0X1S, and T37.0X2A.

Code Identity

ICD-10-CM Code
T37
Billable Status
No — Non-Billable Category
Code Describes
Poisoning by, adverse effect of and underdosing of other systemic anti-infectives and antiparasitics
Short Description
Other systemic anti-infectives and antiparasitics
Chapter
T36-T50
Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT36-T50Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances
CategoryT37Poisoning by, adverse effect of and underdosing of other systemic anti-infectives and antiparasitics
This CodeT37Poisoning by, adverse effect of and underdosing of other systemic anti-infectives and antiparasitics

Specific Coding for Other systemic anti-infectives and antiparasiticsOverview

Non-specific codes like T37 require more characters. Use one of these billable codes instead:

  • T37.0 for Poisoning by, adverse effect of and underdosing of sulfonamides

  • T37.0X for Poisoning by, adverse effect of and underdosing of sulfonamides

  • T37.1 for Poisoning by, adverse effect of and underdosing of antimycobacterial drugs

  • T37.1X for Poisoning by, adverse effect of and underdosing of antimycobacterial drugs

  • T37.2 for Poisoning by, adverse effect of and underdosing of antimalarials and drugs acting on other blood protozoa

  • T37.2X for Poisoning by, adverse effect of and underdosing of antimalarials and drugs acting on other blood protozoa

  • T37.3 for Poisoning by, adverse effect of and underdosing of other antiprotozoal drugs

  • T37.3X for Poisoning by, adverse effect of and underdosing of other antiprotozoal drugs

  • T37.4 for Poisoning by, adverse effect of and underdosing of anthelminthics

  • T37.4X for Poisoning by, adverse effect of and underdosing of anthelminthics

  • T37.5 for Poisoning by, adverse effect of and underdosing of antiviral drugs

  • T37.5X for Poisoning by, adverse effect of and underdosing of antiviral drugs

  • T37.8 for Poisoning by, adverse effect of and underdosing of other specified systemic anti-infectives and antiparasitics

  • T37.8X for Poisoning by, adverse effect of and underdosing of other specified systemic anti-infectives and antiparasitics

  • T37.9 for Poisoning by, adverse effect of and underdosing of unspecified systemic anti-infective and antiparasitics

  • T37.91 for Poisoning by unspecified systemic anti-infective and antiparasitics, accidental (unintentional)

  • T37.92 for Poisoning by unspecified systemic anti-infective and antiparasitics, intentional self-harm

  • T37.93 for Poisoning by unspecified systemic anti-infective and antiparasitics, assault

  • T37.94 for Poisoning by unspecified systemic anti-infective and antiparasitics, undetermined

  • T37.95 for Adverse effect of unspecified systemic anti-infective and antiparasitic

  • T37.96 for Underdosing of unspecified systemic anti-infectives and antiparasitics

Coding GuidelinesGuidance

When coding a poisoning or reaction to the improper use of a medication (e.g., overdose, wrong substance given or taken in error, wrong route of administration), first assign the appropriate code from categories T36-T50. The poisoning codes have an associated intent as their 5th or 6th character (accidental, intentional self-harm, assault and undetermined). If the intent of the poisoning is unknown or unspecified, code the intent as accidental intent. The undetermined intent is only for use if the documentation in the record specifies that the intent cannot be determined. Use additional code(s) for all manifestations of poisonings.

The appropriate 7th character is to be added to each code from block Poisoning by, adverse effect of and underdosing of other systemic anti-infectives and antiparasitics (T37). Use the following options for the applicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027, published by CMS and the National Center for Health Statistics.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to T37: its own notes plus those printed at block T36-T50 and Chapter 19. A note printed at a category, block or chapter applies to every code under it.

Includes

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

From Block T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances applies to 3,186 codes
  • 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

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

On T37 itself
  • anti-infectives topically used for ear, nose and throat (T49.6-)
  • anti-infectives topically used for eye (T49.5-)
  • locally applied anti-infectives NEC (T49.0-)
From Block T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances applies to 3,186 codes
  • toxic reaction to local anesthesia in pregnancy (O29.3-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Block T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances applies to 3,186 codes
  • 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)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes

Code First

The underlying condition named in the note is sequenced before this code.

From Block T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances applies to 3,186 codes
  • 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 a second code, after this one, to fully describe the condition.

From Block T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances applies to 3,186 codes
  • 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-)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • code to identify any retained foreign body, if applicable (Z18.-)

Notes

General instructions on how these codes are used.

From Block T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances applies to 3,186 codes
  • 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.
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • 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.

7th Character

Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.

  • The appropriate 7th character is to be added to each code from category T37
Values for category T37 Encounter: Initial, Subsequent, Sequela
  • Ainitial encounter
  • Dsubsequent encounter
  • Ssequela

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

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Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About T37Overview

Is T37 a billable code?

No. This is a category header that groups the codes for poisoning by, adverse effect of and underdosing of other systemic anti-infectives and antiparasitics, and headers cannot be submitted on claims. Claims for poisoning by, adverse effect of and underdosing of other systemic anti-infectives and antiparasitics need a more specific code from this category, such as T37.0X1A, T37.0X1D, and T37.0X1S.

Can T37 be reported with a code from T49.6?

Not as a rule. The Excludes1 note on T37 lists "anti-infectives topically used for ear, nose and throat (T49.6-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).