MCMedicalCodingSoftware
T78.079A

T78.079AAnaphylactic reaction due to milk and dairy products, unspecified, initial encounter

Billable / specific codeICD-10-CM

T78.079A is a billable, specific ICD-10-CM code for anaphylactic reaction due to milk and dairy products, unspecified, 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 T78

A
initial encounter
D
subsequent encounter
S
sequela

Excludes2 inherited from the categories above T78.079A

Also inherited, and the opposite of Excludes1: these conditions are not part of T78.079A, but a patient can have both, so you may code both.

Written on T78 Adverse effects, not elsewhere classified

  • complications of surgical and medical care NEC (T80-T88)

Other codes that can never be billed with T78.079A

These codes carry an Excludes1 note pointing at T78.079A. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading T78.079A alone.

  • T75Other and unspecified effects of other external causes

Risk adjustment

T78.079A 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

T78.079A is named in 31 Medicare coverage policies 31 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A56559Billing and Coding: Allergy Skin Testing
  • A56559Billing and Coding: Allergy Skin Testing
  • A56612Billing and Coding: CT of the Head
  • A56844Billing and Coding: RAST Type Tests

Code history

What changed, and when. Derived by diffing consecutive CMS release files — which matters when you are defending a code assigned under an earlier edition.

  • addedFY2024-FY2026

    Anaphylactic reaction due to milk and dairy products, unspecified, initial encounter

Related codes at this level

Codes that share T78.079. If T78.079A is not quite right, the correct code is usually one of these.

Questions about T78.079A

Is T78.079A a billable ICD-10-CM code?
Yes. T78.079A is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does T78.079A sit in the tabular list?
Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Other and unspecified effects of external causes (T66-T78).
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.