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T45

T45Poisoning by, adverse effect of and underdosing of primarily systemic and hematological agents, not elsewhere classified

Non-billable headerICD-10-CM

T45 is a non-billable header ICD-10-CM code for poisoning by, adverse effect of and underdosing of primarily systemic and hematological agents, not elsewhere classified. It cannot be billed on its own: choose one of the more specific child codes below. This code also requires a 7th character before it is complete.

This code requires a 7th character

The appropriate 7th character is to be added to each code from category T45

A
initial encounter
D
subsequent encounter
S
sequela

Other codes that can never be billed with T45

These codes carry an Excludes1 note pointing at T45. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading T45 alone.

  • T36Poisoning by, adverse effect of and underdosing of systemic antibiotics
  • T37.5Poisoning by, adverse effect of and underdosing of antiviral drugs
  • T45.1Poisoning by, adverse effect of and underdosing of antineoplastic and immunosuppressive drugs
  • T45.APoisoning by, adverse effect of and underdosing of immune checkpoint inhibitors and immunostimulant drugs

Risk adjustment

T45 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Code to one of these instead T45

11 child codes. Green means billable.

Questions about T45

Is T45 a billable ICD-10-CM code?
No. T45 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does T45 sit in the tabular list?
Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances (T36-T50).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.