Is T63.331A a billable ICD-10-CM code?

Yes. T63.331A is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does T63.331A 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).

T63.331A

T63.331A — Toxic effect of venom of brown recluse spider, accidental (unintentional), initial encounter

Billable / specific codeICD-10-CM

T63.331A is a billable, specific ICD-10-CM code for toxic effect of venom of brown recluse spider, accidental (unintentional), initial encounter. It is valid for submission on a claim.

7th character "A" — initial 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 T63.331A

Also inherited, and the opposite of Excludes1: these conditions are not part of T63.331A, 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 T63.331A

These codes carry an Excludes1 note pointing at T63.331A. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading T63.331A 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

T63.331A 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

T63.331A is named in 15 Medicare coverage policies — 15 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

A56612Billing and Coding: CT of the Head
A56844Billing and Coding: RAST Type Tests
A57043Billing and Coding: RAST Type Tests
A57205Billing and Coding: Oximetry Services

Code history

T63.331A 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 T63.331. If T63.331A is not quite right, the correct code is usually one of these.

Questions about T63.331A

Is T63.331A a billable ICD-10-CM code?: Yes. T63.331A is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does T63.331A 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).