T36.AXUpcomingCategory · further specificity required

Poisoning by, adverse effect of and underdosing of fluoroquinolone antibiotics

Chapters 19 · Inherited instructions

Use additional code

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

T36-T50 · Inherited instructions

Code first

, 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

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-)

Excludes 1

toxic reaction to local anesthesia in pregnancy (O29.3-)

T36 · Inherited instructions

Excludes 1

antineoplastic antibiotics (T45.1-)
locally applied antibiotic NEC (T49.0)
topically used antibiotic for ear, nose and throat (T49.6)
topically used antibiotic for eye (T49.5)

A — initial encounter

D — subsequent encounter

S — sequela

Excludes 2 · 7

Chapters 19 · Injury, poisoning and certain other consequences of external causes (S00-T88)

Excludes 2

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

T36-T50 · Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances (T36-T50)

Excludes 2

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)

More specific codes

T36.AX1Poisoning by fluoroquinolone antibiotics, accidental (unintentional)T36.AX2Poisoning by fluoroquinolone antibiotics, intentional self-harm T36.AX3Poisoning by fluoroquinolone antibiotics, assault T36.AX4Poisoning by fluoroquinolone antibiotics, undetermined T36.AX5Adverse effect of fluoroquinolone antibiotics T36.AX6Underdosing of fluoroquinolone antibiotics

Claims & coverage

When ICD-10-CM is required

For US diagnosis claims covered by HIPAA, ICD-10-CM is required from October 1, 2015.

Use the service date for outpatient/professional claims and the discharge date for hospital inpatient claims. Earlier encounters use ICD-9-CM; each individual code must also be valid for the applicable date.

Official coding guidelines → · CMS ↗

First observed · 2025-10-01

Code history

Latest recorded change · FY2026

ChangedUnchanged

FY2026

Effective from 2025-10-01

Added

Poisoning by, adverse effect of and underdosing of fluoroquinolone antibiotics

Category — select a more specific code

CDC/NCHS · FY2026

All editions (3)

All editions	Effective from	Code history
FY2026	2025-10-01	Added
FY2026 · April	2026-04-01	No tabular change
FY2027	2026-10-01	No tabular change

Code-level instructions

The official Tabular List has no additional instructions at this code level.

Review the instructions inherited from its parent categories below. Inherited instructions ↓

Review the official coding guidelines ↗

Inherited instructions

Chapters 19 · Injury, poisoning and certain other consequences of external causes (S00-T88)

Excludes 2

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

Use additional code

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

Note

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.

T36-T50 · Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances (T36-T50)

Includes

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

Excludes 1

toxic reaction to local anesthesia in pregnancy (O29.3-)

Excludes 2

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)

Code first

, 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

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-)

Note

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.

T36 · Poisoning by, adverse effect of and underdosing of systemic antibiotics

Excludes 1

antineoplastic antibiotics (T45.1-)
locally applied antibiotic NEC (T49.0)
topically used antibiotic for ear, nose and throat (T49.6)
topically used antibiotic for eye (T49.5)

Seventh character

The appropriate 7th character is to be added to each code from category T36

A — initial encounter

D — subsequent encounter

S — sequela

More specific codes

T36.AX1Poisoning by fluoroquinolone antibiotics, accidental (unintentional)Category · further specificity required T36.AX2Poisoning by fluoroquinolone antibiotics, intentional self-harmCategory · further specificity required T36.AX3Poisoning by fluoroquinolone antibiotics, assaultCategory · further specificity required T36.AX4Poisoning by fluoroquinolone antibiotics, undeterminedCategory · further specificity required T36.AX5Adverse effect of fluoroquinolone antibioticsCategory · further specificity required T36.AX6Underdosing of fluoroquinolone antibioticsCategory · further specificity required

Related codes

Official titles and instructions are preserved in their source language. Official sources ↗

T36.AXUpcomingCategory · further specificity required

Poisoning by, adverse effect of and underdosing of fluoroquinolone antibiotics

Chapters 19 · Inherited instructions

Use additional code

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

T36-T50 · Inherited instructions

Code first

, 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

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-)

Excludes 1

toxic reaction to local anesthesia in pregnancy (O29.3-)

T36 · Inherited instructions

Excludes 1

antineoplastic antibiotics (T45.1-)
locally applied antibiotic NEC (T49.0)
topically used antibiotic for ear, nose and throat (T49.6)
topically used antibiotic for eye (T49.5)

A — initial encounter

D — subsequent encounter

S — sequela

Excludes 2 · 7

Chapters 19 · Injury, poisoning and certain other consequences of external causes (S00-T88)

Excludes 2

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

T36-T50 · Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances (T36-T50)

Excludes 2

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)

More specific codes

Claims & coverage

When ICD-10-CM is required

For US diagnosis claims covered by HIPAA, ICD-10-CM is required from October 1, 2015.

Official coding guidelines → · CMS ↗

First observed · 2025-10-01

Code history

Latest recorded change · FY2026

ChangedUnchanged

FY2026

Effective from 2025-10-01

Added

Poisoning by, adverse effect of and underdosing of fluoroquinolone antibiotics

Category — select a more specific code

CDC/NCHS · FY2026

All editions (3)

All editions	Effective from	Code history
FY2026	2025-10-01	Added
FY2026 · April	2026-04-01	No tabular change
FY2027	2026-10-01	No tabular change

Code-level instructions

The official Tabular List has no additional instructions at this code level.

Review the instructions inherited from its parent categories below. Inherited instructions ↓

Review the official coding guidelines ↗

Inherited instructions

Chapters 19 · Injury, poisoning and certain other consequences of external causes (S00-T88)

Excludes 2

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

Use additional code

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

Note

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.

T36-T50 · Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances (T36-T50)

Includes

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

Excludes 1

toxic reaction to local anesthesia in pregnancy (O29.3-)

Excludes 2

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)

Code first

, 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

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-)

Note

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.

T36 · Poisoning by, adverse effect of and underdosing of systemic antibiotics

Excludes 1

antineoplastic antibiotics (T45.1-)
locally applied antibiotic NEC (T49.0)
topically used antibiotic for ear, nose and throat (T49.6)
topically used antibiotic for eye (T49.5)

Seventh character

The appropriate 7th character is to be added to each code from category T36

A — initial encounter

D — subsequent encounter

S — sequela

More specific codes

Related codes

Official titles and instructions are preserved in their source language. Official sources ↗