DxCodebookFY2027 · Oct 1, 2026 – Sep 30, 2027

Block · Chapter 19

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

Block T36-T50 groups 15 categories with 3,186 billable codes in FY2027.

Where it sits

  1. Chapter 19 Injury, poisoning and certain other consequences of external causes (S00-T88)
  2. T36-T50 Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances (T36-T50)

Neighbouring blocks

Categories
15
Billable codes
3,186
CC codes
0
MCC codes
0
HCC V28 codes
218
New FY2027
0

Categories in T36-T50

  • T36

    Poisoning by, adverse effect of and underdosing of systemic antibiotics

    –

    • 198 billable codes
    • 11 with HCC
  • T37

    Poisoning by, adverse effect of and underdosing of other systemic anti-infectives and antiparasitics

    –

    • 144 billable codes
    • 8 with HCC
  • T38

    Poisoning by, adverse effect of and underdosing of hormones and their synthetic substitutes and antagonists, not elsewhere classified

    Reactioninsulin → T38.3-

    • 234 billable codes
    • 13 with HCC
  • T39

    Poisoning by, adverse effect of and underdosing of nonopioid analgesics, antipyretics and antirheumatics

    –

    • 162 billable codes
    • 9 with HCC
  • T40

    Poisoning by, adverse effect of and underdosing of narcotics and psychodysleptics [hallucinogens]

    –

    • 258 billable codes
    • 41 with HCC
  • T41

    Poisoning by, adverse effect of and underdosing of anesthetics and therapeutic gases

    –

    • 126 billable codes
    • 7 with HCC
  • T42

    Poisoning by, adverse effect of and underdosing of antiepileptic, sedative- hypnotic and antiparkinsonism drugs

    –

    • 162 billable codes
    • 9 with HCC
  • T43

    Poisoning by, adverse effect of and underdosing of psychotropic drugs, not elsewhere classified

    Syndromeantidepressant discontinuation → T43.205

    • 354 billable codes
    • 34 with HCC
  • T44

    Poisoning by, adverse effect of and underdosing of drugs primarily affecting the autonomic nervous system

    –

    • 198 billable codes
    • 11 with HCC
  • T45

    Poisoning by, adverse effect of and underdosing of primarily systemic and hematological agents, not elsewhere classified

    –

    • 270 billable codes
    • 15 with HCC
  • T46

    Poisoning by, adverse effect of and underdosing of agents primarily affecting the cardiovascular system

    –

    • 198 billable codes
    • 11 with HCC
  • T47

    Poisoning by, adverse effect of and underdosing of agents primarily affecting the gastrointestinal system

    –

    • 180 billable codes
    • 10 with HCC
  • T48

    Poisoning by, adverse effect of and underdosing of agents primarily acting on smooth and skeletal muscles and the respiratory system

    –

    • 180 billable codes
    • 10 with HCC
  • T49

    Poisoning by, adverse effect of and underdosing of topical agents primarily affecting skin and mucous membrane and by ophthalmological, otorhinorlaryngological and dental drugs

    –

    • 180 billable codes
    • 10 with HCC
  • T50

    Poisoning by, adverse effect of and underdosing of diuretics and other and unspecified drugs, medicaments and biological substances

    –

    • 342 billable codes
    • 19 with HCC

Index main terms

  • Reaction → T38 (2 entries)
  • Hyperinsulinism (functional) → T38 (1 entry)
  • Hypoglycemia (spontaneous) → T38 (1 entry)
  • Misadventure (of) (prophylactic) (therapeutic) → T38 (1 entry)
  • Shock → T38 (1 entry)
  • Syndrome → T43 (1 entry)

Block instructions

Notes

  • 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 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

Excludes1

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

Excludes2

  • abuse and dependence of psychoactive substances (F10-F19) F10 F19
  • abuse of non-dependence-producing substances (F55.-) F55
  • immunodeficiency due to drugs (D84.821) D84.821
  • drug reaction and poisoning affecting newborn (P00-P96) P00 P96
  • pathological drug intoxication (inebriation) (F10-F19) F10 F19

Code first

  • , for adverse effects, the nature of the adverse effect, such as:
  • adverse effect NOS (T88.7) T88.7
  • aspirin gastritis (K29.-) K29
  • blood disorders (D56-D76) D56 D76
  • contact dermatitis (L23-L25) L23 L25
  • dermatitis due to substances taken internally (L27.-) L27
  • nephropathy (N14.0-N14.2) 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) Y63.6 Y63.8 Y63.9
  • underdosing of medication regimen (Z91.12-, Z91.13-) Z91.12 Z91.13

Notes that also apply

Chapter 19 instructions (Notes 2, Excludes2 2, Use additional code 1): printed on the chapter 19 page.