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T63.451D

T63.451DToxic effect of venom of hornets, accidental (unintentional), subsequent encounter

Billable / specific codeICD-10-CMPOA exempt

T63.451D is a billable, specific ICD-10-CM code for toxic effect of venom of hornets, accidental (unintentional), subsequent encounter. It is valid for submission on a claim.

7th character "D" — subsequent encounter

The appropriate 7th character is to be added to each code from category T63

A
initial encounter
D
subsequent encounter
S
sequela

Excludes2 inherited from the categories above T63.451D

Also inherited, and the opposite of Excludes1: these conditions are not part of T63.451D, but a patient can have both, so you may code both.

Written on T63 Toxic effect of contact with venomous animals and plants

  • ingestion of toxic animal or plant (T61.-, T62.-)

Other codes that can never be billed with T63.451D

These codes carry an Excludes1 note pointing at T63.451D. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading T63.451D alone.

  • W64Exposure to other animate mechanical forces
  • W64.XXXAExposure to other animate mechanical forces, initial encounter
  • W64.XXXDExposure to other animate mechanical forces, subsequent encounter
  • W64.XXXSExposure to other animate mechanical forces, sequela
  • W56Contact with nonvenomous marine animal

Risk adjustment

T63.451D 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.

Medicare coverage

T63.451D is named in 20 Medicare coverage policies 20 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A56538Billing and Coding: Allergen Immunotherapy
  • A56538Billing and Coding: Allergen Immunotherapy
  • A56558Billing and Coding: Allergy Testing
  • A56559Billing and Coding: Allergy Skin Testing

Code history

T63.451D has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.

Related codes at this level

Codes that share T63.451. If T63.451D is not quite right, the correct code is usually one of these.

Questions about T63.451D

Is T63.451D a billable ICD-10-CM code?
Yes. T63.451D is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does T63.451D sit in the tabular list?
Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Toxic effects of substances chiefly nonmedicinal as to source (T51-T65).
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.