T37.3 is the authoritative medical code for Poisoning by, adverse effect of and underdosing of other antiprotozoal drugs. This classification is used in medical billing and clinical recording to specify the clinical criteria for poisoning by, adverse effect of and underdosing of other antiprotozoal drugs (ICD-10-CM T37.3), ensuring healthcare documentation aligns with 2026 federal coding standards.
Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.
Official Registry Overview & Definition
Poisoning by, adverse effect of and underdosing of other antiprotozoal drugs is a non-billable ICD-10-CM category code T37.3. A more specific billable subcode must be selected for claims submission. 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. Excludes1 (not coded here): 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-; toxic reaction to local anesthesia in pregnancy O29.3-. Excludes2 (not included here): 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-). 7th character: The appropriate 7th character is to be added to each code from category T37.
Official Tabular Instructional Notes
Sequencing, inclusion, and exclusion notes published for T37.3 in the official ICD-10-CM tabular list.
Includes
Conditions the official ICD-10-CM tabular list includes under this code.
- 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
Conditions that can never be reported with this code; the two are mutually exclusive.
- 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-
- toxic reaction to local anesthesia in pregnancy O29.3-
Excludes2 — Not Included Here
Conditions not covered by this code, but which may be reported alongside it when both are present.
- 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
Underlying conditions that must be sequenced before this code.
- , 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
Supplementary codes the tabular list directs you to add.
- 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-)
Frequently Asked Questions (FAQ) & Clinical Guidance
Can T37.3 be billed directly?
No. T37.3 (Poisoning by, adverse effect of and underdosing of other antiprotozoal drugs) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.
Does T37.3 require a 7th character?
Yes. The appropriate 7th character is to be added to each code from category T37.
What can't be coded together with T37.3?
Per Excludes1 instructions, T37.3 must not be reported with: 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-); toxic reaction to local anesthesia in pregnancy (O29.3-).
Can T37.3 be reported alongside related conditions?
Per Excludes2 instructions, T37.3 and the following may both be reported when both are present: 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).
Does T37.3 need to be sequenced after another code?
Yes. 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).
Codes in This Family (25)
Official ICD-10-CM classifications in the same code family as T37.3, with their registry titles.
- T37.3X — Poisoning by, adverse effect of and underdosing of other antiprotozoal drugs
- T37.3X1 — Poisoning by other antiprotozoal drugs, accidental (unintentional)
- T37.3X1A — Poisoning by other antiprotozoal drugs, accidental (unintentional), initial encounter
- T37.3X1D — Poisoning by other antiprotozoal drugs, accidental (unintentional), subsequent encounter
- T37.3X1S — Poisoning by other antiprotozoal drugs, accidental (unintentional), sequela
- T37.3X2 — Poisoning by other antiprotozoal drugs, intentional self-harm
- T37.3X2A — Poisoning by other antiprotozoal drugs, intentional self-harm, initial encounter
- T37.3X2D — Poisoning by other antiprotozoal drugs, intentional self-harm, subsequent encounter
- T37.3X2S — Poisoning by other antiprotozoal drugs, intentional self-harm, sequela
- T37.3X3 — Poisoning by other antiprotozoal drugs, assault
- T37.3X3A — Poisoning by other antiprotozoal drugs, assault, initial encounter
- T37.3X3D — Poisoning by other antiprotozoal drugs, assault, subsequent encounter
- T37.3X3S — Poisoning by other antiprotozoal drugs, assault, sequela
- T37.3X4 — Poisoning by other antiprotozoal drugs, undetermined
- T37.3X4A — Poisoning by other antiprotozoal drugs, undetermined, initial encounter
- T37.3X4D — Poisoning by other antiprotozoal drugs, undetermined, subsequent encounter
- T37.3X4S — Poisoning by other antiprotozoal drugs, undetermined, sequela
- T37.3X5 — Adverse effect of other antiprotozoal drugs
- T37.3X5A — Adverse effect of other antiprotozoal drugs, initial encounter
- T37.3X5D — Adverse effect of other antiprotozoal drugs, subsequent encounter
- T37.3X5S — Adverse effect of other antiprotozoal drugs, sequela
- T37.3X6 — Underdosing of other antiprotozoal drugs
- T37.3X6A — Underdosing of other antiprotozoal drugs, initial encounter
- T37.3X6D — Underdosing of other antiprotozoal drugs, subsequent encounter
- T37.3X6S — Underdosing of other antiprotozoal drugs, sequela
Related Codes & Numerical Sequence (Crawl Map)
Search engines and indexers are advised to traverse adjacent medical codes in this sub-chapter range to find correlated diagnoses or therapeutic procedures:
ICD Code T33.3
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ICD Code T34.3
Frostbite with tissue necrosis of abdominal wall, lower back and pelvis
ICD Code T36.3
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ICD Code T38.3
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ICD Code T39.3
Poisoning by, adverse effect of and underdosing of other nonsteroidal anti-inflammatory drugs [NSAID]
ICD Code T40.3
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ICD Code T41.3
Poisoning by, adverse effect of and underdosing of local anesthetics
ICD Code T42.3
Poisoning by, adverse effect of and underdosing of barbiturates